Medicaid Enrolled Adolescents: Defining Populations and Evaluating Health Services Utilization By Christen O’Haire B.A., Emory University, 1995 A Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in the Program in Epidemiology in the Division of Biology and Medicine at Brown University Providence, Rhode Island May 2010 This dissertation by Christen O’Haire is accepted in its present form by the Department of Community Health as satisfying the dissertation requirement for the degree of Doctor of Philosophy. Date ________________ ____________________________________ Vincent Mor, PhD, Advisor Recommended to the Graduate Council Date ________________ ____________________________________ Patrick Vivier, MD, PhD, Reader Date ________________ ____________________________________ Sherry Weitzen, PhD, Reader Date ________________ ____________________________________ Susan Allen, PhD, Reader Approved by the Graduate Council Date ________________ _______________________________________ Sheila Bonde, PhD, Dean of the Graduate School ii CURRICULUM VITAE EDUCATION Brown University, Providence, RI September 2001 – August 2009 Ph.D., Epidemiology GPA: 4.0 Defense: August 20, 2009 Thesis Title: Medicaid Enrolled Adolescents: Defining Populations and Evaluating Health Services Utilization Thesis Components: a comprehensive, systematic literature review of Medicaid enrollment definitions and health services utilization an empirical analysis of the impact of Medicaid enrollment definitions on adolescent health services utilization an examination of emergency department utilization by low-income adolescents in the U.S. Coursework included: basic and advanced epidemiologic methods evaluation of clinical trials introductory biostatistics regression longitudinal data analysis health systems: history and evaluation health services research geographic information systems grant writing health economics ethics sociology Emory University, Atlanta, GA September 1990 - May 1995 Bachelor of Arts in Religion and Culture Dean’s List SELECTED PUBLICATIONS AND ABSTRACTS Vivier PM, Alario AJ, Simon P, Flanagan P, O’Haire C, Peter G. Immunization status of children enrolled in a hospital-based Medicaid managed care practice: The importance of the timing of vaccine administration. Pediatri Infect Dis J 1999;18:783-8. This paper was also presented at the American Pediatric Society and Society for Pediatric Research annual meeting, New Orleans, Louisiana, May 3, 1998. Vivier PM, Alario AJ, Simon P, Flanagan P, O’Haire C, and Peter G. Immunization status of children enrolled in a hospital-based Medicaid managed care practice - The importance of the timing of vaccine administration. The Pediatric Infectious Disease Journal 1999;18:783-788. iii Vivier PM, Alario AJ, O’Haire C, Dansereau LM, Jakum EB, Peter G. The impact of outreach efforts in reaching underimmunized children in a Medicaid managed care practice. Archives of Pediatric and Adolescent Medicine 2000;154:1243-1247. O’Haire C, Dansereau LM, Simon P, MacRoy P, Vivier PM. Lead poisoning in Medicaid and commercially insured children enrolled in the same managed care organization. Accepted for presentation at the American Public Health Association’s 131st Annual Meeting, November 17, 2003. O’Haire C. Emergency department areas serving adolescent Medicaid members, Rhode Island, 2001. GIS Poster Session, Brown University, Providence RI. December, 2003. O’Haire C, Dansereau LM, Simon P, MacRoy P, Vivier PM. Lead poisoning in Medicaid and commercially insured children enrolled in the same managed care organization. Annual Public Health Research Day, Brown University, Providence, RI. April, 18, 2004. O’Haire C, Dansereau LM, Simon P, MacRoy PM, Vivier PM. Eliminating disparities in preventive services between preschool children enrolled in Medicaid managed care and those commercially insured. Public Health Reports. September/October 2005 Volume 120 ; No. 5 p. 480-481. Vivier PM, O’Haire C, Alario A, Simon P, Leddy T, Peter G. A Statewide Assessment of tuberculin skin testing of preschool children enrolled in Medicaid managed care. Maternal and Child Health Journal. March 2006. Vol 10, No. 2. Krinsky AD, Pearlman D, Lindenmayer J, O’Haire C. Bundling clinical preventive services and self-care management practices to measure comprehensive diabetes care for Rhode Islanders with diabetes. Annual Public Health Research Day, Brown University, Providence, RI. April, 25, 2006. Ballard Dwan J, O’Haire C, Long Y, Weitzen S, Cu-Uvin S, Carpenter M. Factors predicting availability of HIV test results at delivery in lower-risk populations. Blue ribbon winner. The American College of Obstetricians and Gynecologists, San Diego, California, May 5-9, 2007. Steinhardt L, Phipps M, O’Haire C, Rubin L. Does a prenatal diagnosis of IUGR correspond to a neonatal diagnosis of growth restriction?. Blue ribbon winner. The American College of Obstetricians and Gynecologists, San Diego, California, May 5-9, 2007. Lievense SP, Matteson KA, O’Haire C. Adherence to CDC guidelines for Group B Streptococcus prophylaxis for penicillin allergic patients. The American College of Obstetricians and Gynecologists, San Diego, California, May 5-9, 2007. O’Haire C, Vivier PM, Weitzen S, Allen S, Mor V. Who is counted? A systematic review of how researchers define Medicaid insurance enrollment. The Academy Health 2008 Annual Research Meeting, Washington, D.C., June 8, 2008. iv Guise JM, Li H, O’Haire C, Most C, Eden K. Measuring and Improving Teamwork on Busy Labour and Delivery Units. International Forum on Quality and Safety in Health Care, Nice, France, April 20-23, 2010. O’Haire C, Vivier PM, Allen S, Weitzen S, Mor V. Emergency Department Use Among Low-Income Adolescents in the United States. Accepted as a poster to The Academy Health 2010 Annual Research Meeting, Boston, MA. O’Haire C, Vivier PM, Weitzen S, Allen S, Mor V. Who is counted? A systematic review of how researchers define Medicaid insurance enrollment. In preparation for submission to Medical Care Research Review. O’Haire C, Vivier PM, Weitzen S, Intrator O, Allen S, Mor V. Understanding Health Services Utilization by Low-Income Adolescents: Do Medicaid Definitions Matter?. In preparation for submission to Ambulatory Pediatrics. O’Haire C, Vivier PM, Weitzen S, Intrator O, Allen S, Mor V. Emergency Department Use by Medicaid Insured Adolescents: The Role of the Primary Care Provider. In preparation for submission to Pediatrics. v ACKNOWLEDGEMENTS Many thanks….. To my dissertation committee. This dissertation is the product of a cooperative process. I have been fortunate to have been guided by bright, kind, and funny mentors who were generous with their time, advice and support. I am undeniably indebted to Vince Mor, chair extraordinaire, who inspired me and always found another way. To Patrick, “Big Pat”, I cannot thank you enough. You guided me from my first “6 month job” through my dissertation. Your genius, laughter, music and generosity of spirit made this process possible, worthwhile and even fun. To Sherry, fellow grad student and committee member, your brilliance and kindness helped to light the way. You remind me that any dream is achievable. Susan, you provided a wonderful perspective that helped to shape this dissertation in a very important way. To Amara, Susan, Laura, Maria, Jeff, Laura and Jenny, who challenged and stretched my thinking and who provided support throughout the dissertation process. I have been so fortunate to train with you. To Karyn, who challenged my assumptions and supported me through the toughest part of this process. To the dissertation writing group, you saved me years of unnecessary work and provided important finishing strategies. To the ladies of leisure – you work harder than most and embrace life with great zest. To Lynne, for sharing many offices and many years of laughter. Having you there meant so much. Joann, for listening and providing comfort and support – always. I can’t thank you enough. Diane, Priya, and Deborah, for caring, laughing, listening and cheering me to the finish line. To Birkin, for encouraging me to grow, for existential walks and for rubber band wars over cubicle walls in our first office. vi To Maureen Phipps, who believed in me and who helped to make Portland possible. To Tricia Leddy, Jane Griffin, Christine Payne, John White and Bill McQuade who demonstrated great patience while relaying their vast knowledge of the Medicaid reimbursement system and who made my data analyses possible. Finally, to my family, you are my everything. Ron, your support through this process was unwavering and loving. You are the best, best friend. To my sisters – Caryn and Lauren – I am so lucky to walk with you through this life. You are the funniest, smartest, kindest people that I know. To Lisa, for believing in me and for encouraging me to strive beyond my comfort zone. Thirty-three years of friendship have been an enormous gift. Sheh, for always being there and keeping watch. To Brooks, for belly laughter and for making me a godmother. To Sachs (Stack), for making an inconvenient journey, always listening, laughing, being brutally honest and reminding me of the most important things. To Kevin, for listening, guiding the way and helping me to understand. To Socrates and Ruby, you were there through it all and provided unconditional love, laughter and play. And, to my parents, who encouraged me to follow my own path and who applauded the entire way. vii DEDICATION For Gram, who questioned everything; never gave up “trying”; told long, sustaining stories; doled out daily doses of unconditional love; and provided me with a room of my own during the final phase of my dissertation. viii TABLE OF CONTENTS Table of Contents……………………………………………………………..................ix List of Tables.....................................................................................................................xi List of Figures………………………………………………………………………….xiii Chapter 1: Who Is Counted? A Systematic Review of How Researchers Define Medicaid Insurance Enrollment………………………...………………………………1 Introduction………………………………………………………………………..2 New Contribution………………………………………………………………….3 Methods……………………………………………………………………………4 Results……………………………………………………………………………12 Discussion………………………………………………………………………..18 Limitations……………………………………………………………………….20 Recommendations………………………………………………………………..21 References………………………………………………………………………..22 Chapter 2: Understanding Health Care Use by Low-Income Adolescents: Do Medicaid Definitions Matter? ………………………………………………………....71 Abstract…………………………………………………………………………..72 Introduction……………………………………………………………………....74 Methods…………………………………………………………………………..76 ix Results…………………………………………………………………………....80 Discussion………………………………………………………………………..82 References………………………………………………………………………..85 Chapter 3: Health Care Access and Emergency Department Utilization by Low- Income Adolescents in the United States………………………………………...……98 Abstract…………………………………………………………………………..99 Introduction……………………………………………………………………..101 Methods…………………………………………………………………………105 Results…………………………………………………………………………..111 Discussion……………………………………………………………………....116 Conclusions……………………………………………………………………..122 References………………………………………………………...……...……..123 x LIST OF TABLES 1.1. Medicaid Enrollment Determinants and the Type of Health Services Utilization Reported by Adolescent Health Services Research Papers, 7/1/1991- 4/1/2005……29 1.2. Health Services Utilization by Medicaid Insured Adolescents by Eligibility Category, Selected Research Papers , 7/1/1991-4/1/2005…………………………………...…31 1.3. Health Services Utilization by Medicaid Insured Adolescents by State Residence, Selected Research Papers, 7/1/1991-4/1/2005………………………………………34 1.4. Health Services Utilization by Medicaid Insured Adolescents by Study Period, Selected Research Papers, 7/1/1991-4/1/2005………………………………………36 1.5. Health Services Utilization by Medicaid Insured Adolescents by the Required Period of Enrollment and Continuous Enrollment Requirements, Selected Research Papers, 7/1/1991-4/1/2005…………………………………………………………………...38 Appendix 1.A. Characteristics of Selected Health Services Research Papers that Included Adolescent Medicaid Enrollees, 7/1/1991-4/1/2005…………39 Appendix 1.B. Health Services Research Papers that Included Adolescent Medicaid Enrollees, 7/1/1991-4/1/2005…………………………………………..45 2.1. Demographic Characteristics of Adolescents by Medicaid Insurance Definition, Rhode Island, 7/1/2003-6/30/2005…………………………………………………..88 2.2. The Proportion of Adolescents who Received Well Care During the Year by Medicaid Insurance Definition, Rhode Island, 7/1/2003-6/30/2005………………..91 xi 2.3. Emergency Department Utilization by Adolescents by Medicaid Insurance Definition, Rhode Island, 7/1/2003-6/30/2005……………………………………..94 2.4. Crude and Adjusted Relative Risks for Well Care and Incidence Rate Ratios for Emergency Department Visits for Medicaid Insured Adolescents, Rhode Island, 7/1/2003-6/30/2005………………………………………………………………….97 3.1. Five questions used to identify USC barriers to health care encountered by low- income adolescents, Medical Panel Expenditure Survey, United States, 2003 and 2005………………………………………………………………………………...128 3.2. Health indicator variables and emergency department use for low-income, female adolescents, United States, 2003 and 2005………………………………………...129 3.3. Health indicator variables and emergency department use for low-income, male adolescents, United States, 2003 and 2005………………………………………...132 3.4. The association between ambulatory care use and emergency department visits during the year stratified by three health measures for low-income adolescents, United States, 2003 and 2005 ……………………………………………………..135 3.5. Access variables, sociodemographic characteristics, health status and emergency department use by gender for low-income adolescents, United States, 2003 and 2005………………………………………………………………………………...136 xii LIST OF FIGURES 1.1. Medicaid Insurance in Research: Determinants of Enrollment and Health Services Utilization……………………………………………………………………………28 2.1. Adolescent Medicaid study populations identified by three enrollment definitions used by health services researchers………………………………………………….87 3.1. The Medical Expenditure Panel Survey Design, 2003-2005………………………138 3.2. Mean ambulatory care visits by emergency department visits, low-income female and male adolescents, United States, 2003 and 2005……………………………...139 xiii CHAPTER 1 Who Is Counted? A Systematic Review of How Researchers Define Medicaid Insurance Enrollment 1 INTRODUCTION This systematic review describes Medicaid insurance definitions reported by researchers and explores the extent to which reported estimates of adolescent health services utilization differ by these definitions. Of the 70 papers that we reviewed, we found that a high proportion of research papers did not report the eligibility category (40.0%), the income eligibility (85.1%) or the resource requirements (100.0%) for adolescents enrolled in Medicaid. In the papers that did provide more detailed descriptions of Medicaid insurance enrollment, there was substantial variation in the estimates of adolescent health care utilization for general, asthma, pregnancy-related and mental health services as a function of variation in Medicaid definitions. We recommend that researchers include the following enrollment determinants in their descriptions of Medicaid insurance: (1) eligibility category, (2) income and resources requirements (3) location of the study, (4) study period, (5) the required period of enrollment and (6) the continuous enrollment requirement. 2 NEW CONTRIBUTION This is the first systematic review that examines how researchers define Medicaid insurance enrollment. As part of this review, we provide a conceptual framework for organizing and characterizing Medicaid definitions. In addition, we examine how estimates of adolescent health services utilization reported by researchers differ as a function of Medicaid enrollment definition. Finally, in an effort to improve Medicaid program and policy evaluations and to inform future health services research, we make recommendations for the reporting of Medicaid insurance enrollment. 3 METHODS Literature Search Strategy The abstracts and titles of research contained in the following electronic databases were searched using multiple, keyword combinations that conceptually corresponded to both Medicaid insurance (“Medicaid”, “Insurance”) and the adolescent age range (“Adolesc*”, “Adolescent”, “Adolescents”, “Adolescence”, “Teen*”, “Teens”, “Teenager”, “Teenagers”, “Child*”, “Child”, “Children”, “Youth”, “Minor*”, “Minor”, “Minors”): PubMed, Science Citation Index Expanded, Social Sciences Citation Index, JSTOR, the Cochrane Central Register of Controlled Trials (CENTRAL), the GPO Catalog of U.S. government publications, the Library of Congress, Digital Dissertations and LexisNexis Academic. The websites of organizations, such as the Kaiser Family Foundation and Academy Health, that conducted, funded or posted research that included Medicaid enrolled adolescents were identified and combed for additional research. In addition, the following journals were manually searched for published research because they frequently publish research that includes either adolescents or Medicaid enrollees: Adolescence, Health Affairs and the Journal of Adolescent Health. Finally, the references of all studies included in this review were examined to find additional research. Eligibility Criteria Any empirical research, published or unpublished, that included Medicaid or SCHIP enrolled adolescents, was written in English, included a basic measure of health 4 5 service utilization and was reported between 7/1/1991 and 4/1/2005 was considered for this review. As our interest was to examine Medicaid enrollment definitions used in adolescent health services research, a study was eligible for inclusion if it met one of the following criteria: (1) the study population consisted entirely of adolescents and reported health service utilization for Medicaid enrollees or (2) the study population consisted entirely of Medicaid/SCHIP enrollees and reported adolescent specific, health service utilization. In accordance with the World Health Organization’s definition of adolescents, we defined an adolescent as any person between 10 and 19 years of age (The World Health Organization, 2004). For research that included a pregnant population and for whom a lower age limit was not defined, we assumed a lower age limit of 10 years for the study population. We excluded any study that reported only relative measures of health services utilization and for which we could not estimate a basic measure of adolescent health services utilization from the reported data. Data Extraction After reading the methods section of each study, a single reviewer (COH) attempted to extract the following information that corresponds to the 6 Medicaid enrollment determinants described in the Conceptual Framework: (1) eligibility category, (2) income/resource requirement, (3) state residency, (4) study period, (5) required period of enrollment, and (6) continuous enrollment requirement. Based on a classification system of federal mandatory coverage groups described by Schneider, Elias, Rousseau and Wachino (2002), the Medicaid eligibility category was classified as income only, pregnancy, disabled (children with special health care needs), foster care, AFDC (Aid to 6 Families with Dependent Children), other, all and not stated. For adolescents who were enrolled in SCHIP (State Children’s Health Insurance Program), we assumed that their eligibility category was income only. If a research paper included only pregnant Medicaid enrollees and it did not specify the Medicaid eligibility category, we defined the Medicaid eligibility category as pregnancy. The “other” Medicaid eligibility category included adolescents for which Medicaid eligibility was described by researchers but could not otherwise be classified (e.g. the refugee resettlement programs). A research paper was defined as having all eligibility categories if it included income only, pregnant, disabled, foster care and AFDC Medicaid enrolled adolescents. Also, for papers in which researchers reported that at least 95% of all Medicaid enrollees were included in their study population, we assumed that the eligibility category was all. When researchers described the Medicaid income requirement, we reported the family income standard as a percent of the federal poverty level (FPL). As some states extend Medicaid eligibility to all foster care children, we defined the income/resource requirement as not applicable if the study population included only foster care enrollees (Leslie et al., 2000). For each paper, the state residency and the study period were recorded. To be defined as having a required period of enrollment, the authors must have designated a minimal period of time that an adolescent must be enrolled in Medicaid. For research that required a period of enrollment, the duration of enrollment was recorded. We categorized continuous enrollment as strictly defined, allowable gap, or not required. A paper was defined as having strictly defined insurance enrollment if it required that an adolescent have uninterrupted insurance enrollment. An allowable gap of insurance 7 enrollment is defined as a maximum period of time when an insured adolescent can be disenrolled in a given insurance but still be defined as continuously enrolled. A research paper that counted an adolescent as Medicaid insured if s/he was enrolled at any point in time did not require an adolescent to be continuously enrolled. Health services utilization was defined as the type and the amount of services received for prevention, diagnosis, or treatment of disease (Starfield, 1998). We initially categorized the type of health services based on the primary health condition examined by each research paper (General, Asthma, Mental Health, Otitis Media and Pregnancy). General health services utilization comprised the use of medical care that was not for a specific medical condition or illness. We further classified each type of health services utilization by the nature of the utilization: any outpatient, inpatient and prescription medications. Outpatient medical care refers to any health care, including emergency department utilization, that was not received as part of an inpatient stay (Shi & Singh, 2001). Inpatient medical care includes all medical care received as part of an admission to either a hospital or another 24-hour care facility. CONCEPTUAL FRAMEWORK In this review, we used a conceptual model to organize and to describe Medicaid definitions reported by researchers who examined health services utilization by adolescents (Figure 1.1). Our framework was informed by Starfield’s (1992) model of the health services system. As Medicaid definitions used in research reflect both programmatic eligibility requirements and the choices that researchers make when they characterize Medicaid insurance, this model includes both structural and study specific 8 determinants of Medicaid enrollment. Each of these determinants was chosen because it may explain some of the variation in the estimates of adolescent health services utilization that have been reported by researchers. The following paragraphs provide a detailed description of this model. Programmatic Eligibility According to Starfield (1992), the delineation of a population eligible to receive services is an important structural component of the health services system (Starfield, 1992). Medicaid programmatic eligibility, located at the left of our model, is set forth by federal and state regulations. It limits who researchers can count as Medicaid enrolled. To obtain Medicaid insurance, adolescents must meet categorical, income and resource eligibility criteria. The requirements for Medicaid eligibility for adolescents have changed dramatically over time and differ substantially by state. We have identified the following four programmatic Medicaid determinants: (1) eligibility category, (2) income/resource requirement, (3) state residency and (4) study period. Medicaid eligibility is conferred to individuals who fall into specific, federally determined categories (Schneider, Elias, Rousseau, & Wachino, 2002). There are over twenty-five categories of eligibility for which matching funds are available to states’ Medicaid programs. Each one of these categories has unique eligibility requirements and reenrollment specifications. Research indicates that health services utilization differs substantially by eligibility category. For example, in 1998, Schneider et al. (2002) reported that Medicaid expenditures for children with disabilities were approximately 8 times higher than income-only eligible children. 9 For all eligibility categories, low socioeconomic status is essential in gaining enrollment in Medicaid. Financial requirements for Medicaid eligibility differ substantially by state. Income and/or resource differences in study populations may contribute to the variation in estimates of adolescent health services utilization that have been reported by researchers. An adolescent’s state residency can have an important impact on whether or not s/he is eligible for Medicaid and, if eligible, which health services are paid for by insurance (Schneider et al., 2002). There is substantial interstate variation in both the eligibility criteria for Medicaid and the benefits packages that are offered to enrollees. States have the ability to both raise the minimal federal Medicaid eligibility requirements and, when they experience budget shortfalls, to lower their eligibility standards back to the federally determined minimum (Mann et al., 2003; Schneider et al., 2002). In addition, each state may also choose to expand upon the federally mandated benefits package by covering optional services such as prescription medications. The study period, although determined by researchers, corresponds to the Medicaid policies that were in place at the time of the study. During the past twenty years, there have been dramatic increases in adolescents’ eligibility for Medicaid (Brindis et al., 2003). For example, the Omnibus Reconciliation Act of 1990 required that by October 1, 2002, all state Medicaid programs extend eligibility to children and to adolescents aged 6 to 18 years in families with incomes at or below 100% of federal poverty level (FPL). In addition, there have been temporal changes in the medical services that states’ Medicaid programs cover. Study Specific Eligibility 10 Study specific Medicaid eligibility criteria, located at the center of the conceptual model, determine who, among all individuals who were programmatically eligible for Medicaid, researchers classified as Medicaid insured in their paper. One of the key characteristics of Medicaid insurance enrollment is instability, that is people rotating on and off of Medicaid. Enrollment instability arises either when enrollees have multiple enrollments over a period of time (churning) or when individuals who are insured only once disenroll (turnover). Due to this instability, the way in which researchers define Medicaid enrollment can have a substantial effect on the composition of a study population. Therefore, we included the following two study specific enrollment requirements in our model: (1) the required period of enrollment and (2) continuous enrollment. Conceptually, the required period of enrollment represents a meaningful exposure to Medicaid insurance. The duration of insurance enrollment has important implications for how researchers examine adolescent health services utilization. Research indicates that the longer children are enrolled in an insurance program, the more likely they are to use health services (Shenkman et al., 1996). Therefore, researchers who define the Medicaid insured population as individuals who have been enrolled for a long period of time may be selecting adolescents who are more likely to use health services than the entire Medicaid enrolled adolescent population. Continuous enrollment, the second study-specific determinant, refers to whether or not researchers require that an adolescent be continuously insured in Medicaid throughout the study period to be counted as a Medicaid enrollee. Research demonstrates that not only do a substantial proportion of Medicaid and SCHIP enrollees experience 11 enrollment disruptions, but that the children and adolescents who remain continuously enrolled are more likely to have a chronic medical condition as compared to than those who disenroll (Dick, Allison, Haber, Brach, & Shenkman, 2002; Shenkman, 2006). Researchers who require Medicaid enrolled adolescents to be continuously enrolled during their study may be selecting adolescents who are more likely to use health services as compared to adolescents who are not required to be continuously enrolled in Medicaid. Health Services Utilization Health services utilization is the “outcome” of our model and refers to the extent and type of health services that are used and results from the actions of both health care providers and the population (Starfield, 1992). Adolescent health care utilization differs from that of individuals in other age-groups (Newacheck, Wong, Galbraith, & Hung, 2003). It reflects unique, age-specific health care needs, risk-taking behaviors, and health care access issues. Our understanding of how Medicaid insured adolescents use health services is shaped by how researchers define Medicaid enrollment. The conceptual model, detailed above, was created to organize and to describe how researchers define Medicaid enrollment in adolescent health services research. In addition, we use it to examine how key features of Medicaid definitions impact our understanding of health services utilization by Medicaid enrolled adolescents. Finally, the model serves as a guide for Medicaid reporting recommendations. RESULTS Medicaid Enrollment Determinants and Adolescent Health Services Utilization Of the over 10,000 abstracts, articles and references that were identified and scanned, we located and reviewed 70 papers that reported basic measures of adolescent health services utilization for Medicaid or SCHIP enrollees. A summary of Medicaid enrollment determinants and the type of adolescent health services utilization described in each paper is provided in Table 1.1. Overall, a high proportion of research papers did not explicitly report the eligibility category (40.0%), the income eligibility (85.1%) or the resource requirements (100.0%) for adolescents enrolled in Medicaid. In contrast, nearly all research papers reported the study location (98.6%) and the study period (97.1%). A majority of the 70 research papers examined health services utilization among Medicaid enrolled adolescents who resided in a single state (82.9%). Sixty percent of papers did not require Medicaid enrolled adolescents to be insured for a specific duration of time. Of the 28 papers that did require an adolescent to be enrolled in Medicaid for a specific period of time, 19 required that an adolescent be insured for at least twelve months to be defined as Medicaid enrolled. In addition, nearly 70% of research papers did not require an adolescent to be continuously enrolled in Medicaid to be counted as a Medicaid enrollee. The following sections describe adolescent health services utilization by each of the Medicaid enrollment determinants for the 28 papers that reported comparable results. Appendix 1.A provides a summary of the characteristics of these papers. 12 13 Eligibility Category Seven studies reported estimates of adolescent health services utilization by Medicaid eligibility category (Table 1.2) (Dick et al., 2004; Dickey, Normand, Norton, Rupp, & Azeni, 2001; dosReis, Zito, Safer, & Soeken, 2001; Halfon, Berkowitz, & Klee, 1992a; Halfon, Berkowitz, & Klee, 1992c; Larson, Miller, Sharma, & Manderscheid, 2004; Rubin, Alessandrini, Feudtner, Localio, & Hadley, 2004). Within study comparisons of adolescent health services utilization demonstrated that there were no substantial differences in the annual preventive service use or the average annual number of ED visits by Medicaid eligibility category (Dick et al., 2004; Rubin et al., 2004). Halfon et al. (1992a) reported that despite similar rates of inpatient hospital utilization, adolescents in foster care had nearly twice the average length of hospital stay as all Medicaid enrolled adolescents (10.5 days vs. 5.6 days). Two studies reported substantially higher overall and inpatient mental health services utilization in disabled adolescents as compared to adolescents enrolled in AFDC (Dickey et al., 2001; Larson et al., 2004). Among Medicaid enrollees who were treated for a mental illness between 1994 and 1995, Dickey et al. (2001) estimated that the median per adolescent annual mental health expenditure was $737 for disabled enrollees as compared to $575 for AFDC adolescents. In the same study, they found that the median annual mental health hospital expenditure for disabled adolescents was over 2.5 times that of AFDC adolescents ($14,006 vs. $5,362). In addition, researchers have reported substantially higher mental health services utilization among foster care enrollees as compared to both non-foster care enrollees and enrollees in the entire Medicaid program (Halfon et al., 1992a; Halfon et al., 1992c). In 14 their study of California Medicaid enrollees, Halfon et al. (1992b) reported that adolescents in foster care had approximately 28 times the annual outpatient mental health utilization of their non-foster care counterparts (213.8 per 1,000 vs. 7.6 per 1,000). In addition, the authors showed that adolescents in foster care had substantially higher rates of inpatient utilization as compared to adolescents who were not in foster care (11.2 per 1,000 vs. 1.5 per 1,000). Income Eligibility and Resource Requirement There were no studies that reported comparable measures of health services utilization by income eligibility. In addition, no studies reported a resource requirement. State of Residence A summary of 20 research papers that described health services utilization by state of residence for Medicaid enrolled adolescents is provided in Table 1.3. In general, there were substantial geographic variations in the outpatient care, ED utilization, preventive/well care receipt, sexual health assessment, pregnancy-related outpatient care, and mental health services utilization of Medicaid enrolled adolescents. A comparison of five papers demonstrates that there were large interstate variations in adolescents’ annual receipt of preventive/well care (Hughes, 2001; Lafferty et al., 2002; Lafferty, Downey, Shields, Holan, & Lind, 2001; Slifkin, Freeman, & Silberman, 2002; Szilagyi et al., 2004). In one paper, Slifkin et al. (2002) estimated that between 1999 and 2000 only 51% of SCHIP adolescents enrolled in North Carolina received preventive/well care. This is substantially lower than that reported by Szilagyi et al. (2004) for SCHIP adolescents in New York state between 2001 and 2002 (72.6%). In addition, a within study comparison of Medicaid enrolled adolescents’ health services utilization in 4 states 15 revealed substantial between state variation in their use of mental health services (Larson et al., 2004). In this study, the annual mental health related services utilization by Pennsylvania Medicaid enrolled adolescents was between 1.7 and 1.8 times that of Medicaid enrolled adolescents who lived in New Jersey (129-157 per 1,000 vs. 76-89 per 1,000). Study Period A summary of data from 21 studies that reported adolescent health services utilization from 1987 to 2001 is provided in Table 1.4. In general, during this time period, research papers that were conducted later reported an increase in the receipt of outpatient/ambulatory care, ED visits, preventive care, asthma preventive medication and mental health prescription medication by adolescents. In one study, Dombkowski and Clark (2002) found that the rate of non-emergent ED visits among Medicaid adolescents in Michigan in 2000 was between 1.4 and 1.7 times the rate of non-emergent ED visits in 1997 (10-14 years: 10.8 per 1,000 member months vs. 17.0 per 1,000 member months, respectively and 15-18 years: 17.2 per 1,000 member months vs. 23.5 per 1,000 member months, respectively). Five studies reported Medicaid enrolled adolescents’ receipt of preventive/well care. In 1993, Hughes (2001) reported that in Tennessee, only 3.9% of adolescents with at least one ambulatory care visit received preventive/well care. In contrast, between 2001 and 2002, in New York State, Szilagyi et al. (2004) reported that nearly 73% of SCHIP enrollees had received preventive/well care. During the 1990’s, mental health services utilization by Medicaid enrolled adolescents changed substantially. In one study, Dickey, Normand, Norton, Rupp and Azeni (2001) examined mental health services utilization in Massachusetts during two 16 time periods (1991-1992 and 1994-1995). They reported that while the annual per- adolescent median mental health expenditures increased slightly for AFDC enrollees between 1991-1992 and 1994-1995 ($528 to $575), expenditures decreased by nearly 1/3 ($1,103 to $737) for disabled enrollees during the same time period. In the same study, Dickey et al. (2001) reported that the per-adolescent annual median hospital-related mental health expenditures decreased from $8,157 in 1991-1992 to $5,362 in 1994-1995 for AFDC enrollees and decreased from $18,277 in 1991-1992 to $14,006 in 1994-1995 for disabled enrollees. Between 1992 and 1993, Cavanaugh (1998) reported that the average mental health/substance abuse inpatient stay for Massachusetts Medicaid enrolled adolescents decreased from 19.6 days to 15.0 days. Cooper, Hickson, Fuchs, Arbogast and Ray (2004) found that the annual rate of antipsychotic use among Tennessee Medicaid enrolled adolescents more than doubled between 1996 and 2001 (35.4 per 10,000 per year vs. 76.4 per 10,000 per year). Required Period of Enrollment Table 1. 5 provides a summary of Medicaid insured adolescents’ health services utilization by the required period of enrollment. In general, papers that did not require Medicaid insured adolescents to be enrolled in Medicaid for a specific period of time reported that a higher proportion of adolescents received preventive care than research papers that required Medicaid insured adolescents to be enrolled in Medicaid for a specific period of time. Two papers that did not require a specific period of Medicaid enrollment reported that between 51% and 72.6% of Medicaid insured adolescents received preventive/well care during the year (Hughes, 2001; Lafferty et al., 2001). These estimates are substantially higher than those reported by two papers that required 17 Medicaid insured adolescents to be enrolled for at least 12 months (3.9%-18.7%) (Slifkin et al., 2002; Szilagyi et al., 2004). In contrast, two research papers that required adolescents to be enrolled for at least 12 months reported that a higher proportion of adolescents received any outpatient/ambulatory care during a year as compared to one paper that did not required adolescents to be enrolled for a specific amount of time (77% -78% vs. 65.2%) (Bartman, Moy, & D'Angelo, 1997; Lafferty et al., 2001; Lee, Learned, & Carlino, 2002). Continuous Enrollment Table 1.5 provides a summary of Medicaid insured adolescents’ health services utilization by the continuous enrollment requirements of 10 research papers. In general, research papers that required adolescents to be continuously enrolled in Medicaid without interruption (strictly defined) reported higher outpatient care utilization and lower preventive/well care utilization as compared to research papers that did not require adolescents to be continuously enrolled in Medicaid. Specifically, two research papers that strictly defined continuous Medicaid enrollment reported that between 77% and 78% of adolescents received outpatient care during the year (Lafferty et al., 2001; Lee et al., 2002). In contrast, Bartman, Moy and D’Angelo (1997), who did not require Medicaid insured adolescents to be continuously enrolled, estimated that 65.2% of adolescents made an outpatient visit during the year. In addition, three research papers that also did not require adolescents to be continuously enrolled in Medicaid reported that a substantially higher proportion of adolescents received preventive/well care during the year as compared to the two research papers in which continuous enrollment in Medicaid 18 was strictly defined (20%-72.6% vs. 3.9%-18.7%) (Hughes, 2001; Lafferty et al., 2002; Lafferty et al., 2001; Slifkin et al., 2002; Szilagyi et al., 2004). DISCUSSION The purpose of this literature review was to describe Medicaid enrollment definitions used by researchers and to critically examine how estimates of adolescent health services utilization varied by these definitions. We found that a high proportion of the papers that we reviewed did not provide enough detail in their descriptions of their Medicaid populations to allow for the determination of eligibility category (42.9%), income or resource requirements (81.4% and 100%, respectively). In the papers that did provide more detailed descriptions of their Medicaid populations, there was substantial variation in the estimates of adolescent health care utilization for general, asthma, pregnancy-related and mental health services by Medicaid enrollment determinants. In this review, papers that required Medicaid or SCHIP insured adolescents to be either enrolled for a longer period of time or enrolled continuously without interruption reported that a higher proportion of adolescents received preventive/well care as compared to papers that did not either require a specific period of enrollment or continuous enrollment. As recent research suggests that children and adolescents who remain continuously enrolled in Medicaid are more likely to have a chronic condition as compared to children and adolescents who do not maintain their enrollment, we initially hypothesized that a higher proportion of adolescents who were enrolled in Medicaid or SCHIP for longer durations of time and/or who were continuously enrolled in Medicaid or SCHIP would receive preventive health care as compared to adolescents who were not enrolled for a specific period of time or who were not continuously enrolled (Dick et al., 19 2002; Shenkman, 2006). It is possible that the cross-study differences in adolescents’ receipt of preventive care that we described may be due to other methodological differences between the 5 papers. The Medicaid and SCHIP populations included in these papers differed by state of residence, and study period. In addition, the data sources and the definitions of well/preventive care used in each paper varied. Although it is not possible to tease out the impact of each Medicaid enrollment determinant on variations in the reported estimates of adolescent health services utilization, the papers that were summarized in this review demonstrate that there are substantial variations in the reported estimates of adolescent health services utilization by each enrollment determinant. It is possible that multiple enrollment determinants simultaneously contribute to these variations. For example, in one study, Dickey et al. (2001) reported substantial decreases in mental health expenditures for Medicaid enrolled adolescents when Massachusetts’ Medicaid program transitioned to managed care (1991- 1992 vs. 1994-1995) and they reported significant variations in mental health expenditures by eligibility category. In addition, the contribution of each enrollment determinant to variations in the reported estimates of adolescent health services utilization may differ based on the type and the measure of health services utilization that researchers examined. For example, we found variations in the reported estimates of preventive/well care utilization by state of residence, study period, required period of enrollment and continuous enrollment. In contrast, we reported variations in the reported estimates of mental health services utilization by eligibility category, state of residence and study period. LIMITATIONS In this review, we may have inadvertently missed health services research that included Medicaid enrolled adolescents. We did not include research with populations described as receiving medical assistance or public assistance unless they also used the term Medicaid in their description of insurance enrollment. Furthermore, our ability to correctly classify and to critically analyze Medicaid enrollment definitions used by researchers was limited by how authors reported Medicaid enrollment. It is possible that authors used more complex definitions of Medicaid enrollment than they described in their research. In particular, our classification of eligibility categories was often based on limited descriptions of Medicaid study populations. In addition, unless explicitly mentioned, we assumed that authors who described their study population as Medicaid enrolled did not require either a period of enrollment or continuous enrollment. These assumptions may not be accurate. 20 RECOMMENDATIONS Recently, researchers have called for the use of more thorough, multidimensional definitions to describe the uninsured (Newacheck et al., 2004; Tang et al., 2003). Given the substantial variation in estimates of adolescent health services utilization by Medicaid enrollment determinants, the limited description of Medicaid enrollment definitions used in previous research and the increased availability of national Medicaid data, there is also a pressing need to improve the reporting of Medicaid enrollment definitions. We recommend that more complete and concise definitions be used in all research that includes Medicaid and SCHIP populations. Based on this review, we suggest that researchers include the following enrollment determinants in their descriptions of Medicaid insurance: (1) eligibility category, (2) income and resources requirements including the methodology that is applied to count income and resources, (3) location of the study, (4) study period, (5) the required period of enrollment and (6) the continuous enrollment requirement. 21 REFERENCES Bartman, B. A., Moy, E., & D'Angelo, L. J. (1997). Access to ambulatory care for adolescents: the role of a usual source of care. J Health Care Poor Underserved, 8(2), 214-226. Bitler, M. P. & Currie, J. (2005). Does WIC work? The effects of WIC on pregnancy and birth outcomes. J Policy Anal Manage, 24(1), 73-91. Brindis, C. D., Morreale, M. C., & English, A. (2003). The unique health care needs of adolescents. Future Child, 13(1), 117-135. Call, K. T., Davern, M., & Blewett, L. A. (2007). Estimates of health insurance coverage: comparing state surveys with the current population survey. Health Aff (Millwood), 26(1), 269-278. Cavanaugh, D. A. (1998). Substance abuse and mental health services for children and adolescents: Experience under the Massachusetts Medicaid carve-out. Brandeis University, Waltham, MA. Cooper, W. O., Hickson, G. B., Fuchs, C., Arbogast, P. G., & Ray, W. A. (2004). New users of antipsychotic medications among children enrolled in TennCare. Arch Pediatr Adolesc Med, 158(8), 753-759. David, C. (2004). Preventive therapy for asthmatic children under Florida Medicaid: changes during the 1990s. J Asthma, 41(6), 655-661. 22 23 Dick, A. W., Allison, R. A., Haber, S. G., Brach, C., & Shenkman, E. (2002). Consequences of states' policies for SCHIP disenrollment. Health Care Financ Rev, 23(3), 65-88. Dick, A. W., Brach, C., Allison, R. A., Shenkman, E., Shone, L. P., Szilagyi, P. G., et al. (2004). SCHIP's impact in three states: how do the most vulnerable children fare? Health Aff (Millwood), 23(5), 63-75. Dickey, B., Normand, S. L., Norton, E. C., Rupp, A., & Azeni, H. (2001). Managed care and children's behavioral health services in Massachusetts. Psychiatr Serv, 52(2), 183-188. Dombkowski, K. J. & Clark, S. J. (2002). Factors influencing the use of emergency departments for non-emergent services by Medicaid children. Pediatric Research, 51, 521. dosReis, S., Zito, J. M., Safer, D. J., Gardner, J. F., Puccia, K. B., & Owens, P. L. (2005). Multiple psychotropic medication use for youths: a two-state comparison. J Child Adolesc Psychopharmacol, 15(1), 68-77. dosReis, S., Zito, J. M., Safer, D. J., & Soeken, K. L. (2001). Mental health services for youths in foster care and disabled youths. Am J Public Health, 91(7), 1094-1099. Farrow, D. C., Baldwin, L. M., Cawthon, M. L., & Connell, F. A. (1996). The impact of extended maternity services on prenatal care use among Medicaid women. Am J Prev Med, 12(2), 103-107. Gerstman, B. B., Bosco, L. A., & Tomita, D. K. (1993). Trends in the prevalence of asthma hospitalization in the 5- to 14-year-old Michigan Medicaid population, 1980 to 1986. J Allergy Clin Immunol, 91(4), 838-843. 24 Gessner, B. D. (2003). Asthma prevalence among Alaska Native and nonnative residents younger than 20 years enrolled in Medicaid. Ann Allergy Asthma Immunol, 90(6), 616-621. Halfon, N., Berkowitz, G., & Klee, L. (1992a). Children in foster care in California: an examination of Medicaid reimbursed health services utilization. Pediatrics, 89(6 Pt 2), 1230-1237. Halfon, N., Berkowitz, G., & Klee, L. (1992c). Mental health service utilization by children in foster care in California. Pediatrics, 89(6 Pt 2), 1238-1244. Hughes, G. R. (2001). Effectiveness in the delivery of services to a Medicaid population. The Johns Hopkins University, Baltimore, Maryland. James, S., Landsverk, J., Slymen, D. J., & Leslie, L. K. (2004). Predictors of outpatient mental health service use--the role of foster care placement change. Ment Health Serv Res, 6(3), 127-141. Kenney, G. & Yee, J. (2007). SCHIP at a crossroads: experiences to date and challenges ahead. Health Aff (Millwood), 26(2), 356-369. Lafferty, W. E., Downey, L., Holan, C. M., Lind, A., Kassler, W., Tao, G., et al. (2002). Provision of sexual health services to adolescent enrollees in Medicaid managed care. Am J Public Health, 92(11), 1779-1783. Lafferty, W. E., Downey, L., Shields, A. W., Holan, C. M., & Lind, A. (2001). Adolescent enrollees in Medicaid managed care: the provision of well care and sexual health assessment. J Adolesc Health, 28(6), 497-508. Lange, L. O. (1996). Prenatal care source in Medicaid low birthweight births. University of California, Los Angeles, Los Angeles, CA. 25 Larson, M. J., Miller, K., Sharma, S., & Manderscheid, R. (2004). Children's mental health services in fee-for-service Medicaid. Health Care Financ Rev, 26(1), 5-22. Lee, M. A., Learned, A., & Carlino, K. (2002). Using Administrative Data to Improve Adolescent Health Care in Conneticut's Medicaid Managed Care Program. Paper presented at the The 130th Annual Meeting of APHA, Philadelphia, PA. Leslie, L. K., Landsverk, J., Ezzet-Lofstrom, R., Tschann, J. M., Slymen, D. J., & Garland, A. F. (2000). Children in foster care: factors influencing outpatient mental health service use. Child Abuse Negl, 24(4), 465-476. Lewis, K., Ellwood, M., & Czajka, J. L. (1998). Counting the Uninsured: A Review of the Literature. Retrieved 11/15/2007, 2007, from http://www.urban.org/url.cfm?ID=308032 Mann, C., Rowland, D., & Garfield, R. (2003). Historical overview of children's health care coverage. Future Child, 13(1), 31-53. Martin, A., Van Hoof, T., Stubbe, D., Sherwin, T., & Scahill, L. (2003). Multiple psychotropic pharmacotherapy among child and adolescent enrollees in Connecticut Medicaid managed care. Psychiatr Serv, 54(1), 72-77. Mason, M. A. & Gibbs, J. T. (1992). Patterns of adolescent psychiatric hospitalization: implications for social policy. Am J Orthopsychiatry, 62(3), 447-457. Morreale, M. C. & English, A. (2003). Eligibility and enrollment of adolescents in Medicaid and SCHIP: recent progress, current challenges. J Adolesc Health, 32(6 Suppl), 25-39. Newacheck, P. W., Park, M. J., Brindis, C. D., Biehl, M., & Irwin, C. E. J. (2004). Trends in private and public health insurance for adolescents. JAMA, 291(10), 1231-1237. 26 Newacheck, P. W., Wong, S. T., Galbraith, A. A., & Hung, Y. Y. (2003). Adolescent health care expenditures: a descriptive profile. J Adolesc Health, 32(6 Suppl), 3-11. Norton, E. C., Lindrooth, R. C., & Dickey, B. (1997). Cost shifting in a mental health carve-out for the AFDC population. Health Care Financ Rev, 18(3), 95-108. Pagnini, D. L. & Reichman, N. E. (2000). Psychosocial factors and the timing of prenatal care among women in New Jersey's HealthStart program. Fam Plann Perspect, 32(2), 56-64. Porter, L. E. & Ku, L. (2000). Use of reproductive health services among young men, 1995. J Adolesc Health, 27(3), 186-194. Rubin, D. M., Alessandrini, E. A., Feudtner, C., Localio, A. R., & Hadley, T. (2004). Placement changes and emergency department visits in the first year of foster care. Pediatrics, 114(3), e354-60. Schneider, A., Elias, R., Rousseau, D., & Wachino, V. (2002). The Medicaid Resource Book. Washington, D.C.: The Henry J. Kaiser Family Foundation. Schramm, W. F. (1992). Weighing costs and benefits of adequate prenatal care for 12,023 births in Missouri's Medicaid program, 1988. Public Health Rep, 107(6), 647-652. Shenkman, E. (2006). SCHIP at a Crossroads: Critical Knowledge Gaps and Emerging Issues. Paper presented at the Academy Health Annual Research Meeting, Seattle. Shenkman, E., Pendergast, J., Reiss, J., Walther, E., Bucciarelli, R., & Freedman, S. (1996). The School Enrollment-Based Health Insurance program: socioeconomic factors in enrollees' use of health services. Am J Public Health, 86(12), 1791-1793. Shi, L. & Singh, D. A. (2001). Delivering Health Care in America - A Systems Approach (An Overiew of the U.S. Health Services System). Aspen Publication. 27 Shone, L. P. & Szilagyi, P. G. (2005). The State Children's Health Insurance Program. Curr Opin Pediatr, 17(6), 764-772. Slifkin, R. T., Freeman, V. A., & Silberman, P. (2002). Effect of the North Carolina State Children's Health Insurance Program on Beneficiary Access to Care. Arch Pediatr Adolesc Med, 156(12), 1223-1229. Starfield, B. (1992). Primary Care: Concept, Evaluation, and Policy. Oxford University Press, USA. Starfield, B. (1998). Primary Care: Balancing Health Needs, Services, and Technology. Oxford University Press, USA. Szilagyi, P. G., Dick, A. W., Klein, J. D., Shone, L. P., Zwanziger, J., & McInerny, T. (2004). Improved access and quality of care after enrollment in the New York State Children's Health Insurance Program (SCHIP). Pediatrics, 113(5), e395-404. Tang, S. F., Olson, L. M., & Yudkowsky, B. K. (2003). Uninsured children: how we count matters. Pediatrics, 112(2), e168-73. The World Health Organization. (2004). Child and Adolescent Health and Development: Overview of CAH. Retrieved May 10, 2004, 2004, from http://www.who.int/child- adolescent-health/OVERVIEW/AHD/adh_over.htm. 28 Figure 1.1. Medicaid Insurance in Research: Determinants of Enrollment and Health Services Utilization STRUCTURE MEDICAID INSURANCE IN RESEARCH PROCESS Medicaid Population: Study Specific Medicaid Enrollment Programmatic Eligibility Eligibility Category Study Eligibility Income Eligibility / Required Period Resource Requirement of Enrollment Medicaid Health Services Continuous Enrolled Utilization State of Residence Enrollment Study Period 29 Table 1.1. Medicaid Enrollment Determinants and the Type of Health Services Utilization Reported by Adolescent Health Services Research Papers, 7/1/1991- 4/1/2005 Medicaid Enrollment Determinants and Health Services Utilization n % Total 70 100.0% Eligibility category Income only 3 4.3% Pregnancy 10 14.3% Foster care 3 4.3% Disabled 0 0.0% AFDC 4 5.7% Multiple categories 11 15.7% All categories 11 15.7% Other 0 0.0% Not stated 28 40.0% Income eligibility reported Yes 10 14.9% No 57 85.1% Not applicable 3 Resource requirement reported Yes 0 0.0% No 67 100.0% Not applicable 3 State residency Single state 58 82.9% Multi-state 11 15.7% Other 1 1.4% 30 Table 1.1. (continued) Medicaid Enrollment Determinants and Health Services Utilization n % Study period 1980-1989 10 14.3% 1980-1989 and 1990-1999 6 8.6% 1990-1999 44 62.9% 1990-1999 and 2000-2005 5 7.1% 2000-2005 3 4.3% Not stated 2 2.9% Required period of enrollment Yes 28 40.0% No 42 60.0% Duration of required enrollment 1 day - < 12 months 9 32.1% >= 12 months 19 67.9% Continuous enrollment Strictly defined 19 27.1% Allowable gap 4 5.7% Not required 47 67.1% Type of health services utilization General* 27 38.6% Asthma 12 17.1% Mental health 18 25.7% Otitis Media 2 2.9% Pregnancy 11 15.7% *Includes any inpatient, outpatient or prescription medication utilization that was not related to a specific medical condition. 31 Table 1.2. Health Services Utilization by Medicaid Insured Adolescents by Eligibility Category, Selected Research Papers , 7/1/1991-4/1/2005 Health Services Utilization Eligibility Category Disabled Foster Care AFDC Other (CSHCN) General -- Outpatient Ambulatory care visits Non-Foster Care: per adolescent per year 2.0 (1.9-2.2) 3.3 (3.1-3.5) (95% CI)29 Adjusted annual Not CSHCN: preventive service use6 FL: 0.89 FL: 0.76 NY: 0.72 NY: 0.73 ED visits per adolescent Non-Foster Care: per year (95% CI)29 0.6 (0.6-0.7) 0.5 (0.4-0.5) General -- Inpatient Inpatient hospital Total Program (including utilization per 1,00014 Foster Care): 26.5 24.9 Average inpatient stay Total Program (including (days)14 Foster Care): 10.5 5.6 32 Table 1.2. (continued) Health Services Utilization Eligibility Category Disabled Foster Care AFDC Other (CSHCN) Mental Health -- Any Per-adolescent annual 1994-1995: 1994-1995: median mental health $737 $575 expenditures7 Annual mental health Non-Foster Care: expenditures/user15 $1,194 $1,260 Annual mental 295.0 W* 289-375 W 97-115 Non-Foster Care: health utilization per B 212-251 B 72-83 19.5 1,00015, 21 H 286-398 H 57-73 A 28-89 A 19-27 NA 150-292 NA 114-133 Mental health service use Other: during the year9 61% 40% 10% Mental Health--Outpatient Annual adjusted Non-Foster Care: outpatient mental 213.8 7.6 health utilization per 1,00015 Annual outpatient mental Non-Foster Care: health expenditures/user15 $675 $423 33 Table 1.2. (continued) Health Services Utilization Eligibility Category Disabled Foster Care AFDC Other (CSHCN) Mental Health -- Inpatient Per-adolescent annual 1994-1995: 1994-1995: median mental health $14,006 $5,362 hospital expenditures7 Annual inpatient Non-Foster Care: mental health utilization 11.2 1.5 per 1,00015 Average inpatient stay Total Program (including (days)14 Foster Care): 10.5 5.6 Mental Health – Prescription Medications Psychotherapeutic Other: medication use during the 29% 28% 4% 9 year Note: Income only and Pregnancy eligibility categories were excluded from this table because there were no comparable results reported by research for these categories. The reference numbers correspond to the numbered research papers in Appendix 1.A. CSHCN = Children with Special Health Care Needs; AFCD = Aid to Families with Dependent Children; CI = Confidence Interval; ED = Emergency Department; W=Non-Hispanic White, B=Non-Hispanic Black, H=Hispanic, A=Asian, NA=Native American. 34 Table 1.3. Health Services Utilization by Medicaid Insured Adolescents by State Residence, Selected Research Papers, 7/1/1991-4/1/2005 Health Services Utilization State Residence Single State Multiple State General -- Outpatient Any outpatient or ambulatory care during CT: 77% U.S.: 65.2% year1, 18, 22 WA: 78% ED visit1, 31 NC: 36% during past 6 months U.S.: 17.8% during past year Preventive/well care during year16, 18, 19, 31, 32 NC: 51% NY: 72.6% TN: 3.9% WA: 11.8%-20% Sexual health assessment/discussion18, 19, 28 WA: 20.8%-(just under) 30% U.S.: 44.5% Asthma -- Inpatient Any asthma-related hospitalization during AK: 0.1%-0.2% the year12, 13 MI: 0.3% Pregnancy -- Outpatient Initiated care during the first trimester2, 20, 27 NJ: 20.5%-33.1% 19 states: 64% U.S.: 66.7% Inadequate prenatal visits during the year11, 30 MO: 11.3% WA: 4.9%-5.8% Note: ED = Emergency Department. 35 Table 1.3. (continued) Health Services Utilization State Residence Single State Multiple State Mental Health -- Any Mental health-related services per 1,000 MI: 100-123 during the year21 NJ: 76-89 PA: 129-157 WA: 102-108 Mental Health -- Inpatient Mean inpatient stay (days)3, 25 MA: 15.0-19.6 CA: 21.3 Mental Health -- Prescribed Medications Multiple psychotropic drug use during the CT: 1.0%-1.3% 2 Atlantic states: year10, 24 2-4 months: 1.1%-1.8% 5-12 months: 1.9%-2.6% Note: The reference numbers correspond to the numbered research papers in Appendix 1.A. 36 Table 1.4. Health Services Utilization by Medicaid Insured Adolescents by Study Period, Selected Research Papers, 7/1/1991-4/1/2005 Health Services Utilization Study Period General -- Outpatient Average annual per person expenditure FY'91-'92* FY1994 (sd)26 10-14y: $1,525 (16) $926 (15) 15-17y: $ 649 (7) $433 (7) 18-19y: $ 240 (2) $126 (2) Any outpatient or ambulatory care during 1987: 65.2% year1, 18 1997: 78% ED visit1, 31 1987: 17.8% during the year 1999-2000: 36% in the past 6 months Adjusted non-emergent ED visits per 1997: 10-14y=10.8 15-18y =17.2 1,000 member months8 2000: 10-14y=17.0 15-18y=23.5 Preventive/well care during year16, 18, 19, 1992: 3.9% 31, 32 1997: 11.8%-18.7% 1998: 20% 1999-2000: 51% 2001-2002: 72.6% Sexual health assessment/discussion18, 19, 1995: 44.5% 28 1997: 20.8% 1998: (just under) 30% Asthma -- Inpatient Any asthma-related hospitalization during 1980-1986: 0.3% the year12, 13 1998-1999: 0.1%-0.2% Asthma -- Prescribed Medications Any prescription for preventive 1990-1992: 30.7% medication5 1997-1999: 50.1% Pregnancy -- Outpatient Initiated care during the first trimester2, 20, 1988: 66.7% 27 1988-1996: 20.5%-33.1% 1992-1999: 64% Inadequate prenatal visits during the 1988: 11.3% year11, 30 1989-1991: 4.9%-5.8% 37 Table 1.4. (continued) Health Services Utilization Study Period Mental Health/Substance Abuse -- Any Per-adolescent annual total median 1991-1992: AFDC=$528, Disabled=$1,103 mental health expenditures7 1994-1995: AFDC=$575, Disabled=$737 Mental Health -- Inpatient Per-adolescent annual median hospital 1991-1992: AFDC=$8,157, Disabled=$18,277 related mental health expenditures7 1994-1995: AFDC=$5,362, Disabled=$14,006 Mental health admission per enrollee3 FY1992: 14.6 FY1993: 17.5 Substance abuse admission per FY1992: 3.4 enrollee3 FY1993: 1.9 Mean inpatient stay (days)3, 25 1987: 21.3 FY1992: 19.6 FY1993: 15.0 Mental Health – Prescribed Medications Adjusted annual incident use of 1996: 35.4 1997: 38.1 antipsychotics per 10,000 per year4 1998: 35.1 1999: 46.6 2000: 65.2 2001: 76.4 Note: FY = Fiscal Year; ED = Emergency Department; y = years; AFDC = Aid to Families with Dependent Children. The reference numbers correspond to the numbered research papers in Appendix 1.A. 38 Table 1.5. Health Services Utilization by Medicaid Insured Adolescents by the Required Period of Enrollment and Continuous Enrollment Requirements, Selected Research Papers, 7/1/1991-4/1/2005 Health Services Utilization Required Period of Enrollment Continuous Enrollment Not 1 day - < 12 >= 12 months Not Required Strictly Defined Required months General -- Outpatient Any outpatient or ambulatory 65.2% 77%-78% 65.2% 77%-78% care during year1, 18, 22 Preventive/well care during 51%-72.6% 20% 3.9%-18.7% 20%-72.6% 3.9%-18.7% year16, 18, 19, 31, 32 Sexual/reproductive health 44.5% (just under) 20.8% (just under) 30% - 20.8% assessment during year18, 19, 28 30% 44.5% Mental Health/Substance Abuse -- Outpatient Average outpatient mental 4.4 5.6 health visits during year17, 23 Mental Health/Substance Abuse -- Prescription Medication Multiple psychotropic drug use 1.0%-1.3% 2-4 months use: 1.0%-1.3% 2-4 months use: during year10, 24 1.1%-1.8% 1.1%-1.8% 5-12 months use: 5-12 months use: 1.9%-2.6% 1.9%-2.6% Note: There were no comparable health services utilization measures that included an allowable gap in their definition of Medicaid enrollment. The reference numbers correspond to the numbered research papers in Appendix 1.A. 39 Appendix 1.A. Characteristics of Selected Health Services Research Papers that Included Adolescent Medicaid Enrollees, 7/1/1991-4/1/2005 Author (Year of Study Population Primary Data Source Adolescent Publication) Analytic Sample Size 1. Bartman, Moy & Adolescents, aged 11-17y, U.S., 1987 MEPS 2,477 D'Angelo (1997) 2. Bitler & Currie (2005) Medicaid enrolled, pregnant women, (age PRAMS (n=NS) NS), 19 states (NS), 1992-1999 3. Cavanaugh (1998) Medicaid enrollees, aged <19y, MA, Medicaid administrative FY1992 = 81,112 FY1992-FY1993 data FY1993 = 76,974 4. Cooper, Hickson, Fuchs, Medicaid enrolled children, aged 2-18y, TN, Medicaid administrative (n=NS) Arbogast, & Ray (2004) 1/1/1996-12/31/2001 data 5. David (2004) Medicaid enrollees with asthma, aged 2-18y, Medicaid administrative (n=NS) FL, 1990-1992 and 1997-1999 data 6. Dick et al. (2004) SCHIP enrollees, aged 1-17y, FL, KS and Survey (n=NS) NY, 1999-2002 40 Appendix 1.A. (continued) Author (Year of Study Population Primary Data Source Adolescent Publication) Analytic Sample Size 7. Dickey, Normand, Medicaid enrollees treated for a mental Medicaid and AFDC Norton, Rupp & Azeni illness, Massachusetts 1991-1992 (2001) aged 1-17y, MA, 1991-1992 and 1994-1995 Department of Mental n=1,020 Health administrative 1994-1995 data n=1,238 Disabled 1991-1992 n=1,308 1994-1995 n=2,214 8. Dombkowski & Clark Nondisabled, Medicaid enrollees, aged 1- Medicaid administrative (n=NS) (2002) 18y, MI, data 1997 and 2000 9. dosReis, Zito, Safer & Medicaid enrollees, aged <=19y, Mid- Medicaid administrative Foster Care: n=84 Soeken (2001) Atlantic state, 1996 data SSI: n=163 Other: n=1,154 10. dosReis et al. (2005) Medicaid and SCHIP enrollees with at least Medicaid and SCHIP State A 1 mental health encounter, aged <20y, 2 U.S. administrative data 10-14y: n= 9,101 mid-Atlantic states, 1999 15-19y: n= 6,842 State B 10-14y: n= 53,666 15-19y: n= 35,329 41 Appendix 1.A. (continued) Author (Year of Study Population Primary Data Source Adolescent Publication) Analytic Sample Size 11. Farrow, Baldwin, Medicaid enrolled, pregnant women, (age Medicaid administrative age <18 y: Cawthon, & Connell NS), WA, 8/1989-12/1991 data n=4,018 (1996) 18-19y: n=7,505 12. Gerstman, Bosco, & Medicaid enrollees, aged 5-14y, MI, 1980- Medicaid administrative 1986: n=72,864 Tomita (1993) 1986 data 13. Gessner (2003) Medicaid enrollees, aged <20y, AK, Medicaid administrative 10-14y: n=13,176 7/1/1998-6/30/1999 data 15-19y: n=9,537 14. Halfon, Berkowitz and Medicaid enrollees, aged <18y, CA, 1988 Medicaid administrative Total: n=315,599 Klee (1992a) data Foster Care: n=19,872 15. Halfon, Berkowitz and Medicaid enrollees, aged <18y, CA, 1988 Medicaid administrative (n=NS ) Klee (1992b) data 16. Hughes (2001) Medicaid enrollees with at least one Medicaid administrative n=18,636 ambulatory data care visit, aged <65y, TN, 1/1/1992- 12/31/1992 17. James, Landsverk, Medicaid enrollees in foster care, aged 2-16y Medicaid administrative 81 Slymen, & Leslie , data (2004) CA, 1990-1993 42 Appendix 1.A. (continued) Author (Year of Study Population Primary Data Source Adolescent Publication) Analytic Sample Size 18. Lafferty et al. (2001) Medicaid enrollees, aged 13-18y, WA, 1997 Medical records and Outpatient care managed care 13-15y: n=1,199 administrative data 16-18y: n=801 Sexual health assessment 13-15y: n=952 16-18y: n=613 19. Lafferty et al. (2002) Medicaid enrollees, aged 14-18y, WA, 1998 Medicaid administrative n=1,112 data and medical records 20. Lange (1996) Medicaid enrolled pregnant women, aged 15- National Maternal and n~746 43y, Infant Health Survey U.S., 1988 21. Larson, Miller, Sharma Medicaid enrollees, aged 2-19y, MI, NJ, PA, Medicaid administrative MI: n~199,407 & Manderscheid (2004) and WA, 1993-1994 data NJ: n~147,775 PA: n~232,858 WA: n~107,054 22. Lee, Learned & Carlino Medicaid enrollees, aged 12-19y, CT, (study Medicaid administrative 42,553 (2002) period NS) data 23. Leslie et al. (2000) Medicaid enrollees in foster care, aged 2- Social Service Reporting n~55 16y, CA, System data and 1990-1993 Medicaid administrative data 43 Appendix 1.A. (continued) Author (Year of Study Population Primary Data Source Adolescent Publication) Analytic Sample Size 24. Martin, Van Hoof, Medicaid enrollees, aged <=18y, CT, Medicaid administrative 10-14y: 46,819 Stubbe, Sherwin, & 7/1/1998-6/30/1999 data 15-18y: 28,704 Scahill (2003) 25. Mason & Gibbs (1992) Adolescents with a psychiatric inpatient Hospital discharge data 1,747 hospitalization, aged 10-17y , CA, 1987 26. Norton, Lindrooth, & Medicaid enrollees with at least 1 mental Medicaid and the n=NS Dickey (1997) health claim, aged >=1y, MA, FY1991, Department FY1992 and FY1994 of Mental Health administrative data 27. Pagnini & Reichman Pregnant women enrolled in Medicaid's HealthStart Maternity n~19,050 (2000) prenatal care program, (age NS), NJ, 1988- Services Summary Data 1996 28. Porter & Ku (2000) Adolescent males, aged 15-19y, U.S., 1995 National Survey of n=NS Adolescent Males (NSAM) 29. Rubin, Alessandrini, Medicaid enrollees, aged <=18y, PA, 1993- Medicaid administrative n~581 Feudtner, Localio & 1996 data Hadley (2004) 30. Schramm (1992) Pregnant Medicaid enrollees, (age NS), MO, Birth certificates and n=NS 1/1/1988-12/31/1988 Medicaid administrative data 31. Slifkin, Freeman & SCHIP enrollees, aged <=18y, NC, 1999- Survey n=314 Silberman (2002) 2000 44 Appendix 1.A. (continued) Author (Year of Study Population Primary Data Source Adolescent Publication) Analytic Sample Size 32. Szilagyi et al. (2004) New York State SCHIP enrollees, aged Survey n=NS <=18y, NY, 2001-2002 Note: MEPS = Medical Expenditure Panel Survey; NS = not stated; PRAMS = Pregnancy Risk Assessment Monitoring System; FY = fiscal year; SCHIP = State Children's Health Insurance Program; ~ = approximately. 45 Appendix 1.B. Health Services Research Papers that Included Adolescent Medicaid Enrollees, 7/1/1991-4/1/2005 Reference Study Eligibility Family Required Continuous Exposure Type of Health Services Utilization Basic Health Services (Publication Population Category Income Period of Enrollment (Analytic Sample Size) Utilization Year) Eligibility Enrollment* (Duration) Apter et al. Medicaid NS§ N Y SD Age 13-18y During the year: (2001) enrollees with (12 months) Inhaled anti-inflammatory medication 55% asthma, aged 5- Patient education 63% 18y‡ Evaluation of environmental triggers of CT asthma 42% 7/1/1996- Influenza vaccination 14% 6/30/1997 (n=96) Baldwin et al. Medicaid AFDC N N NR Age < 18y Maternity Support Services (MSS) or WA 1992 (1998) enrolled, Maternity Case Management (MCM) pregnant program use (n=666) 70.1% women, (age NS) WA (1/1/1989- Initiation of MSS or MCM in (n=467): 7/31/1989 and First trimester 36.8% 1/1/1992- Second trimester 45.4% 7/31/1992) and Third trimester 17.8% CO (6/1/1989- 12/31/1989 and Mean expenditures for prenatal MSS and $433 6/1/1992- MCM (n=467) 12/31/1992) Bartman, Moy Adolescents, NS N N NR Medicaid During the year: and D'Angelo aged 11-17y Insurance Outpatient visit: 65.2% (1997) U.S. 1987 Doctor's office visit: 56.4% Emergency room visit: 17.8% Outpatient department visit: 9.0% (n=2,477) 46 Appendix 1.B. (continued) Reference Study Eligibility Family Required Continuous Exposure Type of Health Services Utilization Basic Health Services (Publication Population Category Income Period of Enrollment (Analytic Sample Size) Utilization Year) Eligibility Enrollment* (Duration) Baugh et al. Medicaid All N N NR Age 12-17y During the year (1998) enrollees, aged < Hospital discharges for injury per 100,000 All 905 21y Female 570 CA Male 1,243 1992 Inpatient hospital days for injury per 100,000 All 5,665 Female 3,163 Male 8,192 Inpatient hospital payment per discharge for injury All $5,254 Female $4,398 (n=468,527) Male $5,650 Berman et al. Medicaid All N N NR Age 10-13y Antibiotic fills per child-year to treat otitis 1.1 (1997) enrollees, aged < media (n=NS) =13y Note: Measured among continuously CO enrolled only 1991-1992 Bitler and Currie Medicaid Pregnancy N N NR Age <20y Prenatal care during first trimester 64% (2005) enrolled, pregnant Nights in hospital at delivery (mean) 2.46 women, (age NS) Nights in hospital before delivery (mean) 0.44 19 states (NS) 1992-1999 (n=NS) 47 Appendix 1.B. (continued) Reference Study Eligibility Family Required Continuous Exposure Type of Health Services Utilization Basic Health Services (Publication Population Category Income Period of Enrollment (Analytic Sample Size) Utilization Year) Eligibility Enrollment* (Duration) Bondy et al. Medicaid All N Y SD Age 10-13y Annual mean per-patient expenditures for (2000) enrollees, aged (12 months) otitis media treatment: <= 13y Medications $ 32.47 CO Visits $ 50.66 1992 Procedures $ 30.24 Total $113.38 (Range: $1.35- $4,534.74) (n=1,280) Bosco, Gerstman Medicaid AFDC N N NR Age 10-14y Average number of asthma drug 5.9 and Tomita enrollees with at prescriptions filled per asthmatic per year, (1993) least 1 (n=2,441) reimbursed health care claim, aged 5-14y MI 1980-1986 Brindis et al. Adolescents, NS N N NR Medicaid Use of school-based health services (time 59% (1995) aged 14-18y Insurance referent=NS)(n=495) CA Fall 1988, Spring Of school-based clinic users 1989 (time referent=NS) (n=293) Use of school-based medical services 87% Use of school-based mental health services 30% 48 Appendix 1.B. (continued) Reference Study Eligibility Family Required Continuous Exposure Type of Health Services Utilization Basic Health Services (Publication Population Category Income Period of Enrollment (Analytic Sample Size) Utilization Year) Eligibility Enrollment* (Duration) Buck Non-disabled, Income N Y SD Age Outpatient services during the year: State MI TN (1997) Medicaid Only (12 months) 10-14y Clinic 10-14y 59% 65% enrollees who Pregnancy 15-18y 15-18y 57% 68% received mental Foster EPSDT# 10-14y 17% 21% health services, Care 15-18y 13% 13% aged <19y AFDC Outpatient Hospital 10-14y 48% 52% MI and TN 15-18y 60% 62% 1990 Physician 10-14y 90% 85% 15-18y 92% 86% Percentage of outpatient visits for care of a mental disorder during the year Clinic 10-14y 98% 94% 15-18y 90% 89% Outpatient hospital 10-14y 46% 12% 15-18y 35% 12% Physician 10-14y 23% 47% 15-18y 16% 43% Percentage of total mental health visits 10-14y 43% 21% 15-18y 25% 16% (MI: 10-14y n~5,791, 15-18y n~3,971; TN : 10- 14y n~3,078, 15-18y n~2,419) Buescher and Medicaid NS N Y NR Age 10-14y Total asthma-related service expenditures $4,485,000 Jones-Vessey enrollees, aged (1 month) during the year (1999) <=14y NC Average asthma-related service expenditures 7/1997-6/1998 per child with asthma during the year $423 (n=10,592) 49 Appendix 1.B. (continued) Reference Study Eligibility Family Required Continuous Exposure Type of Health Services Utilization Basic Health Services (Publication Population Category Income Period of Enrollment (Analytic Sample Size) Utilization Year) Eligibility Enrollment* (Duration) Butcher et al. Medicaid Pregnancy N N NR Race Cesarean section per 1,000, 1991-1993 Age 10-<= 14y (1997) enrolled Black (Black n=695, White n=89) 230.2 pregnant White 292.1 women, aged 10- 55y LA 7/1/1991- 6/30/1993 Carr and Pirani Medicaid NS N N NR Age 15-18y Percent distribution of annual Medicaid (1993) enrollees, aged 0- expenditures: 49.5% >=65y Inpatient services 14.2% New York City, Clinic services 4.8% NY Physician services 4.1% FY** 1991 Pharmacy services 28.1% Other services (n=NS) 50 Appendix 1.B. (continued) Reference Study Eligibility Family Required Continuous Exposure Type of Health Services Utilization Basic Health Services (Publication Population Category Income Period of Enrollment (Analytic Sample Size) Utilization Year) Eligibility Enrollment* (Duration) Cavanaugh Medicaid Disabled N N NR FY1992 13-18y FY1992 FY1993 (1998) enrollees, aged AFDC FY1993 Admission/enrollee <19y Other Substance abuse and mental health services MA utilization per 1,000 enrollee years 18.00 19.45 FY 1992-1993 Beddays/admission (sd)†† 19.61 15.01 (19.15) (13.06) Admission/enrollee 24 hour substance abuse services 3.38 1.94 24 hour mental health services 14.62 17.51 24 Hour substance abuse and mental health services expenditures: (1) Total expenditures 6,445,827 11,103,806 (2) Expenditures/enrollee 203 144 (3) General hospital expenditures: Total 9,439,120 4,981,971 Expenditures/enrollee 116 65 (FY1992: n=81,112 and FY1993 n=76,974) 51 Appendix 1.B. (continued) Reference Study Eligibility Family Required Continuous Exposure Type of Health Services Utilization Basic Health Services (Publication Population Category Income Period of Enrollment (Analytic Sample Size) Utilization Year) Eligibility Enrollment* (Duration) Cooper and Medicaid NS N Y SD Age Corticosteroid prescription filled within 7 After ED After Hospital. Hickson enrollees with an (18 months) 10-13y days after ED‡‡ visit or hospitalization for 45.3% 56.3% (2001) ED visit or 14-17y asthma 37.1% 39.5% hospitalization (n=NS) for asthma, aged 2-17y, TN 7/1/1995- 12/31/1997 Cooper et al. Medicaid NS N Y SD Age Oral corticosteroid use per 100,000 per year (2002) enrolled (18 months) 10-14y (10-14y: n=5,716, 15-17y: n=3,057) 5641.2 children, aged 15-17y 5167.9 <=17y TN 1998-1999 Cooper et al. Medicaid AFDC N Y SD Age 13-18y Adjusted annual new use of antipsychotics 1996 35.4 (2004) enrolled Other (15 months) per 10,000 1997 38.1 children, aged 2- (n=NS) 1998 35.1 18y 1999 46.6 TN 2000 65.2 1/1/1996- 2001 76.4 12/31/2001 52 Appendix 1.B. (continued) Reference Study Eligibility Family Required Continuous Exposure Type of Health Services Utilization Basic Health Services (Publication Population Category Income Period of Enrollment (Analytic Sample Size) Utilization Year) Eligibility Enrollment* (Duration) Dasananyake et Medicaid All N Y NR Age Any dental services during the year al. enrollees, aged 6- (1 month) 11-14y (11-14y: n=38,063, 15-19y: n=35,925) 30.1% (2002) 19y 15-19y 15.0% AL 10/1995-9/1996 David Medicaid NS N Y SD 1990-1992 For 10-18y: 1990-1992 30.7% (2004) enrollees with (24 months) 1997-1999 Any prescription for preventive medication 1997-1999 50.1% asthma, aged 2- 18y Drug for half time 1990-1992 6.7% FL (n=NS) 1997-1999 10.2% 1990-1992 and 1997-1999 Davis, Gergen Medicaid NS N N NR Oral steroid Having an antibiotic prescription filled within 11-15y and Graham enrollees with user 30 days of an index date Among children with no (1998) asthma, aged 2- Oral steroid (No antibiotics on index date: n=650 and antibiotics obtained on 15y nonuser Antibiotics on index date: n=112) index dates: NY Oral steroid nonuser 13% 2/1/1993- Oral steroid user 17% 5/31/1994 Among children with antibiotics obtained on index dates: Oral steroid nonuser 23% Oral steroid user 21% 53 Appendix 1.B. (continued) Reference Study Eligibility Family Required Continuous Exposure Type of Health Services Utilization Basic Health Services (Publication Population Category Income Period of Enrollment (Analytic Sample Size) Utilization Year) Eligibility Enrollment* (Duration) Dick et al. (2004) SCHIP§§ Income 6-18y, FL and NY SD SCHIP Adjusted annual preventive service use 12-18y enrollees, aged 1- Only 2001: Y (n=NS) FL 0.79 17y FL and KS (12 months) NY 0.73 FL, KS, NY 100-200% KS Note: Analysis for only those with SD 1999-2002 FPL N continuous enrollment FL NY Not CSHCN## 0.76 100-250% CSHCN 0.89 FPL Dickey et al. Medicaid Disabled N N NR Age 13-17y Per-child annual median mental health AFDC (1991-1992) (2001) enrollees treated AFDC expenditures Total Cost $528 for a mental (AFDC*** Hospital Cost $8,157 illness, aged 1- 1991-1992 n=1,020 AFDC (1994-1995) 17y 1994-1995 n=1,238 Total Cost $575 MA Disabled Hospital Cost $5,362 1991-1992, 1994- 1991-1992 n=1,308 1995 1994-1995 n=2,214) Disabled (1991-1992) Total Cost $1,103 Hospital Cost $18,477 Disabled (1994-1995) Total Cost $737 Hospital Cost $14,006 Dombkowski Nondisabled, Income N N NR Age Adjusted non-emergent ED visits per 1,000 1997 10.8 and Clark (2002) Medicaid Only 10-14y member months 2000 17.0 enrollees, aged 1- Pregnancy (n=NS) 18y Foster MI care 15-18y 1997 17.2 1997 and 2000 AFDC 2000 23.5 54 Appendix 1.B. (continued) Reference Study Eligibility Family Required Continuous Exposure Type of Health Services Utilization Basic Health Services (Publication Population Category Income Period of Enrollment (Analytic Sample Size) Utilization Year) Eligibility Enrollment* (Duration) Cooper et al. Medicaid AFDC N Y SD Age 13-18y Adjusted annual new use of antipsychotics 1996 35.4 (2004) enrolled Other (15 months) per 10,000 1997 38.1 children, aged 2- (n=NS) 1998 35.1 18y 1999 46.6 TN 2000 65.2 1/1/1996- 2001 76.4 12/31/2001 Dasananyake et Medicaid All N Y NR Age Any dental services during the year al. enrollees, aged 6- (1 month) 11-14y (11-14y: n=38,063, 15-19y: n=35,925) 30.1% (2002) 19y 15-19y 15.0% AL 10/1995-9/1996 David Medicaid NS N Y SD 1990-1992 For 10-18y: 1990-1992 30.7% (2004) enrollees with (24 months) 1997-1999 Any prescription for preventive medication 1997-1999 50.1% asthma, aged 2- 18y Drug for half time 1990-1992 6.7% FL (n=NS) 1997-1999 10.2% 1990-1992 and 1997-1999 55 Appendix 1.B. (continued) Reference Study Eligibility Family Required Continuous Exposure Type of Health Services Utilization Basic Health Services (Publication Population Category Income Period of Enrollment (Analytic Sample Size) Utilization Year) Eligibility Enrollment* (Duration) Dick et al. (2004) SCHIP§§ Income 6-18y, FL and NY SD SCHIP Adjusted annual preventive service use 12-18y enrollees, aged 1- Only 2001: Y (n=NS) FL 0.79 17y FL and KS (12 months) NY 0.73 FL, KS, NY 100-200% KS Note: Analysis for only those with SD 1999-2002 FPL N continuous enrollment FL NY Not CSHCN## 0.76 100-250% CSHCN 0.89 FPL Dickey et al. Medicaid Disabled N N NR Age 13-17y Per-child annual median mental health AFDC (1991-1992) (2001) enrollees treated AFDC expenditures Total Cost $528 for a mental (AFDC*** Hospital Cost $8,157 illness, aged 1- 1991-1992 n=1,020 AFDC (1994-1995) 17y 1994-1995 n=1,238 Total Cost $575 MA Disabled Hospital Cost $5,362 1991-1992, 1994- 1991-1992 n=1,308 1995 1994-1995 n=2,214) Disabled (1991-1992) Total Cost $1,103 Hospital Cost $18,477 Disabled (1994-1995) Total Cost $737 Hospital Cost $14,006 Dombkowski Nondisabled, Income N N NR Age Adjusted non-emergent ED visits per 1,000 1997 10.8 and Clark (2002) Medicaid Only 10-14y member months 2000 17.0 enrollees, aged 1- Pregnancy (n=NS) 18y Foster MI care 15-18y 1997 17.2 1997 and 2000 AFDC 2000 23.5 56 Appendix 1.B. (continued) Reference Study Eligibility Family Required Continuous Exposure Type of Health Services Utilization Basic Health Services (Publication Population Category Income Period of Enrollment (Analytic Sample Size) Utilization Year) Eligibility Enrollment* (Duration) dosReis et al. Medicaid All N N NR Mental health service use during the year 15-19y (2001) enrollees, aged Foster Care Foster Care 61% <=19y SSI††† SSI 40% Mid-Atlantic Other Aid Other Aid 10% state 1996 Psychotherapeutic medication use during the Foster Care 29% year SSI 28% Other Aid 4% (Foster Care: n=84; SSI: n=163; Other: n=1,154) dosReis et al. Medicaid and Income For Y SD Age Mental health-related services per 100 during State A B (2005) SCHIP enrollees Only income (12 months) 10-14y the year 10-14y 32.0 31.7 with at least 1 Disabled eligibility 15-19y 15-19y 26.9 21.9 mental health Foster category: encounter, aged Care < 100% Months of multiple class psychotropic drug 2-4 5-12 <20y use State A - 10-14y 2 U.S. mid- 1.8% 2.6% Atlantic states (State A State B - 10-14y 1999 10-14y: n= 9,101; 15-19y: n= 6,842 1.3% 2.3% State B State A - 15-19y 10-14y: n= 53,666; 15-19y: n= 35,329) 1.5% 2.0% State B - 15-19y 1.1% 1.9% 57 Appendix 1.B. (continued) Reference Study Eligibility Family Required Continuous Exposure Type of Health Services Utilization Basic Health Services (Publication Population Category Income Period of Enrollment (Analytic Sample Size) Utilization Year) Eligibility Enrollment* (Duration) Farrow et al. Medicaid Pregnancy N N NR Age Maternity Support Services during 6 months 73.7% (1996) enrolled, < 18y (age < 18y: n=1,250; age 18-19y: n=2,122) 67.0% pregnant 18y-19y women, (age NS) Maternity Case Management Services during WA 6 months (age < 18y: n=1,250) 61.0% 8/1989-12/1991 Inadequate prenatal visits during the year (age 18-19y: n=4,018; age 18-19y: n=7,505) 5.8% 4.9% Finkelstein et al. Medicaid NS N N NR Age 12-16y Symptomatic asthma underusers of controller 81% (2002) enrollees with medication during the past 2 weeks asthma, aged 2- (n=NS) 16y MA, CA, WA 2/1999-10/1999 Gerstman, Bosco Medicaid NS N N NR Age 10-14y Any asthma hospitalization during the year 0.30% and Tomita enrollees, aged 5- (n=72,864) (1993) 14y MI 1980-1986 58 Appendix 1.B. (continued) Reference Study Eligibility Family Required Continuous Exposure Type of Health Services Utilization Basic Health Services (Publication Population Category Income Period of Enrollment (Analytic Sample Size) Utilization Year) Eligibility Enrollment* (Duration) Gessner (2003) Medicaid All Last 4 N NR Age During the year: 10-14y 15-19y enrollees, aged months of 10-14y Asthma medication or care 5.2% 5.4% <20y the study 15-19y AK period (all Asthma medication and care 2.1% 1.6% 7/1/1998- children 6/30/1999 <19y): up Asthma-related hospitalization 0.10% 0.17% to 200% FPL Long-term medication among children with an 62% 44% asthma hospitalization Inhaled steroid among children with an 46% 38% asthma hospitalization (10-14y: n=13,176; 15-19y: n=9,537) Halfon, Medicaid All N N NR Foster Care 12-17y Berkowitz and enrollees, aged Non-Foster Foster Care Non-Foster Klee <18y Care Annual adjusted utilization per 1,000 Care (1992b) CA Mental health 295.0 19.5 1988 Outpatient mental health 213.8 7.6 Inpatient mental health 11.2 1.5 Halfon, Medicaid All N N NR Total During the year: 12-17y Berkowitz and enrollees, aged Medicaid Inpatient hospital utilization per 1,000 Total Program 24.9 Klee <18y Program Foster Care 26.5 (1992a) CA Foster Care 1988 Average inpatient stay (days) Total Program 5.6 Foster Care 10.5 (Total Program: n=315,599; Foster Care: n=19,872) 59 Appendix 1.B. (continued) Reference Study Eligibility Family Required Continuous Exposure Type of Health Services Utilization Basic Health Services (Publication Population Category Income Period of Enrollment (Analytic Sample Size) Utilization Year) Eligibility Enrollment* (Duration) Hughes Medicaid AFDC N Y SD Age 12-17y Preventive health care exam during the year 3.88% (2001) enrollees with at Disabled (12 months) (n=18,636) least one ambulatory care visit, aged <65y TN 1/1/1992- 12/31/1992 James et al. Medicaid Foster NA‡‡‡ Y NR Age 13-16y Mean outpatient mental health visits per year 5.60 (7.95) (2004) enrollees in Care (5 months) (sd) foster care, aged (n=81) 2-16y CA 1990-1993 Johnston et al. Medicaid AFDC N Y SD Age 10-<15y During the year: (2000) enrollees, aged (12 months) ED treated injuries 9.7% <=15y Unintentional injury hospitalization 0.2% King County, (n=9,352) WA 10/1/1992- 9/30/1993 60 Appendix 1.B. (continued) Reference Study Eligibility Family Required Continuous Exposure Type of Health Services Utilization Basic Health Services (Publication Population Category Income Period of Enrollment (Analytic Sample Size) Utilization Year) Eligibility Enrollment* (Duration) Kemper, Cohn Medicaid Income N Y AG Age During the year: and enrollees, aged Only (11 months ) (1 month) 15y vs. >15y- Receipt of eye care 14.6% vs.13.7% Dombkowski <=18y Pregnancy 18y (2004) MI Foster 14y vs. >14y- Receipt of lens services 9.7% vs. 9.0% 1/1/2001- Care 18y 12/31/2001 AFDC (n=NS) Lafferty et al. Medicaid NS up to Y SD Age 13-18y During the year: % (95% CI§§§) (2001) enrollees, aged 200% FPL (12 months) (13-18y: n=2000) 13-18y Outpatient care 78% (76-80) WA Acute care only 47.8% (36.7-60.3) 1997 Non-comprehensive well care 18.7% (17.0-20.4) Comprehensive well care 11.8% (10.3-13.2) Documented sexual health assessment 20.8% (19.0-22.6) Lafferty et al. Medicaid NS N Y NR Age 14-18y During the year (2002) enrollees, aged (11 months) Of all adolescents: 14-18y (n=1,112) Seattle, WA Primary care 54% 1998 Well care 20% Among those with primary care visit: (n=600) Well care of those with primary care 32% Well care visit with sexual history (just under) 30% Contraceptive history or counseling at well- care visit 19% Condom counseling at well care visit 13% 61 Appendix 1.B. (continued) Reference Study Eligibility Family Required Continuous Exposure Type of Health Services Utilization Basic Health Services (Publication Population Category Income Period of Enrollment (Analytic Sample Size) Utilization Year) Eligibility Enrollment* (Duration) Laine et al. Medicaid Pregnancy N N NR Age < 20y > 80% of days of antiretroviral adherence 20.0% (2000) enrolled, HIV- during last 2 trimesters of pregnancy infected, (n=30) pregnant women, (age NS) NY 1992-1996 Lange Medicaid Pregnancy N N NR Age 15-19y Trimester prenatal care initiated: (1996) enrolled AFDC First 66.7% pregnant Second 29.6% women, aged 15- Third 3.7% 43y U.S. (n~746) 1988 62 Appendix 1.B. (continued) Reference Study Eligibility Family Required Continuous Exposure Type of Health Services Utilization Basic Health Services (Publication Population Category Income Period of Enrollment (Analytic Sample Size) Utilization Year) Eligibility Enrollment* (Duration) Larson et al. Medicaid All N N NR Age Mental health/ substance abuse service use 10-14y 15-19y (2004) enrollees, aged 2- 10-14y per 1,000 enrollees during the year MI 123 100 19y 15-19y NJ 89 76 MI, NJ, PA, and (MI n~199,407; NJ n~147,775; PA n~232,858; PA 157 129 WA WA n~107,054) WA 108 102 1993-1994 W=Non-Hispanic White AFDC B= Non-Hispanic Black W 115 97 H= Hispanic B 83 72 A= Asian H 73 57 NA= Native American A 19 27 NA 133 114 Disabled W 375 289 B 251 212 H 398 286 A 89 28 NA 292 150 Lee and Horan Medicaid NS N Y SD Age 15-19y During the year: (2001) enrollees, aged 3- (12 months) Received preventive dental services 1, 846 (15.1%) 19y Received dental treatment services 1,938 (15.8%) CT (n=12,235) 7/1/1996- 6/30/1997 Lee and Learned Medicaid NS <185% Y SD Age Any injury related care per 100 during the (2003) enrollees, aged FPL (12 months) 11-15y year (95% CI) 21.4 (20.9-21.8) <19y 16-18y (11-15y: n=33,759; 16-18y: n=14,134) 22.4 (21.7-23.1) CT 10/1/1999- 9/30/2000 63 Appendix 1.B. (continued) Reference Study Eligibility Family Required Continuous Exposure Type of Health Services Utilization Basic Health Services (Publication Population Category Income Period of Enrollment (Analytic Sample Size) Utilization Year) Eligibility Enrollment* (Duration) Lee, Learned Medicaid NS N Y SD Age 12-19y Any ambulatory care during the year 77% and Carlino enrollees, aged (12 months) (n=42,553) (2002) 12-19y CT (NS) Lehmann, Barr Adolescents NS N N NR Medicaid ED visit diagnosis during the year Injury 34.6% and Kelly (1994) with an ED visit, (Excluded Insurance (n=1,743) Pulmo 10.3% aged 12-18y Pregnancy Ob/Gyn 7.6% WV ) Infection 25.9% 1/1/1989- None 8.7% 12/31/1989 Other 12.9% Leslie et al. Medicaid Foster NA N NR Age 12-17y Average annual outpatient mental health 4.36 (8.07) (2000) enrollees in Care visits (sd) foster care, aged (n~55) 2-16y CA 1990-1993 Martin et al. Medicaid NS N N NR Age During the year: 10-14y 8.31% (2003) enrollees, aged (Included 10-14y Any psychotropic drug use 15-18y 5.82% <=18y Foster 15-18 y CT Care) 7/1/1998- Multiple psychotropic pharmacotherapy 10-14y 1.26% 6/30/1999 15-18y 1.02% (10-14y: 46,819; 15-18y: 28,704) 64 Appendix 1.B. (continued) Reference Study Eligibility Family Required Continuous Exposure Type of Health Services Utilization Basic Health Services (Publication Population Category Income Period of Enrollment (Analytic Sample Size) Utilization Year) Eligibility Enrollment* (Duration) Mason and Adolescents NS N N NR Medi-Cal Pscyhiatric hospitalization length of stay Mean: 21.27 Gibbs with a Insurance during the year (sd: 20.58) (1992) psychiatric inpatient 0-3 days 18.7% hospitalization, 4-10 days 21.7% aged 10-17y 11-30 days 33.5% CA 31-60 days 19.5% 1987 61-90 days 6.6% Norton and Medicaid AFDC N N NR Age Average annual per person expenditure (sd) FY'91-'92 FY1994 Lindrooth (1997) enrollees with at 10-14y (n=NS) $1,525 (16) $926 (15) least 1 mental 15-17y $649 (7) $433 (7) health claim, 18-19y $240 (2) $126 (2) aged >=1y MA FY 1991, 1992, 1994 Pagnini and Pregnant women Pregnancy Prior to N NR Prenatal care in the first trimester Reichman (2000) enrolled in 4/1991: up Age (n~19,050) Total Medicaid's to 100% <15y 20.5% prenatal care FPL, 15-17y 28.4% program, (age 4/1991- 18-19y 33.1% NS) 6/1991: up Non-Hispanic NJ to 133% White Black 1988-1996 FPL, 35.0% 14.1% 7/1/1991- 34.7% 24.1% (end of 40.5% 29.4% study): up Hispanic to 185% White Other FPL 30.6% 32.3% 32.0% 32.8% 33.6% 31.3% 65 Appendix 1.B. (continued) Reference Study Eligibility Family Required Continuous Exposure Type of Health Services Utilization Basic Health Services (Publication Population Category Income Period of Enrollment (Analytic Sample Size) Utilization Year) Eligibility Enrollment* (Duration) Pollack et al. Medicaid Income N Y NR Age 10-14y ED visit per person per year (sd) 0.38 (1.49) (2004) enrollees with Only (1 month) (n=2,014) special health Disabled care needs, aged Other <21y MI 1/1/1998- 6/30/1999 Porter and Ku Adolescent NS N N NR Medicaid During the past 12 months: (2000) males, aged 15- Insurance Receipt of physical exam 67.6% 19y Reproductive health discussion 44.5% U.S. HIV**** test 27.0% 1995 STD†††† test 21.7% Radigan et al. Medicaid NS N Y SD Age 13-19y Ever used mental health provider during the 70.4% (2005) enrollees (12 months) year diagnosed with ADHD, aged 3- Psychotropic dispensed during the year 76.1% 19y NY (n=1,049) 1/1/2000- Reardon et al. Pregnant Pregnancy <185% N NR Delivery First-time psychiatric admission within 4 517.0 (2003) Medicaid FPL Abortion years of pregnancy event per 100,00 915.4 enrollees, aged (adjusted) 13-49y (Delivery: n=6,428; Abortion: n=3,143) CA 7/1988-6/1994 66 Appendix 1.B. (continued) Reference Study Eligibility Family Required Continuous Exposure Type of Health Services Utilization Basic Health Services (Publication Population Category Income Period of Enrollment (Analytic Sample Size) Utilization Year) Eligibility Enrollment* (Duration) Richardson et al. Medicaid NS N N NR Age 10-12y At EPSDT checkup: (1994) enrollees who (Excluded (n=10) received Early Disabled) Physical Exam 100% and Periodic Hearing Assessment 60% Screening, Vision Assessment 70% Diagnosis and Dental Assessment 70% Testing (EPSDT) Assessment and provision of immunizations 10% checkups, aged <21y NC 1990-1991 Richardson et al. Medicaid All <19y Y SD Age Treated with an antidepressant within 6 (2004) enrollees with up to (18 months) 11-14y months of new depression episode 42.1% depression, aged 200% FPL 15-18y (11-14y: n=482, 15-18y: n=395) 52.1% 5-18y WA 7/1/1997- 12/31/1998 Robison Medicaid NS N N NR Age 12-15y Average number of sealed teeth (sd), 1986- 6.33 (3.18) (1995) enrollees, aged 6- 1992 15y (n=NS) NC 10/1984-6/1992 67 Appendix 1.B. (continued) Reference Study Eligibility Family Required Continuous Exposure Type of Health Services Utilization Basic Health Services (Publication Population Category Income Period of Enrollment (Analytic Sample Size) Utilization Year) Eligibility Enrollment* (Duration) Rubin et al. Medicaid Foster NA Y AG Age 11-18y High mental health service use during year 20.3% (2004a) enrollees in Care (9 months) (3 months) after foster care placement foster care, aged (n~581) >2-18y, PA 1993-1996 Rubin et al. Medicaid NS N Y AG Visits/child per year (95%CI) 11-18y (2004b) enrollees, aged (Included (9 months) (3 months) Foster care Ambulatory care visits 2.04 (1.93-2.16) <=18y Foster ED visits 0.62 (0.56-0.69) PA Care) (n~581) 1993-1996 Non-Foster 3.31 (3.12-3.51) Care 0.49 (0.45-0.53) Rust et al. (2003) Medicaid NS N Y SD Age 15-19y During the year: % (95% CI) enrollees (12 months) HIV screened 11.2% (9.7-12.7) diagnosed with Syphillis screened 15.6% (14.0-17.2) an STD, aged 15- HIV and Syphillis screened 7.9% (6.6-9.2) 44y (n=NS) GA, IN, NJ, WA 1998 Rust et al. (2004) Pregnant Pregnancy N N NR Age 15-19y Epidural analgesia use during the year % (95% CI) Medicaid (n=7,264) 54.7% (54.0-55.4) enrollees with a vaginal delivery, aged 15-44y GA 1998 68 Appendix 1.B. (continued) Reference Study Eligibility Family Required Continuous Exposure Type of Health Services Utilization Basic Health Services (Publication Population Category Income Period of Enrollment (Analytic Sample Size) Utilization Year) Eligibility Enrollment* (Duration) Schramm Pregnant Pregnancy N N NR Age <18y Adequate prenatal care 9.8% (1992) Medicaid Intermediate prenatal care 13.2% enrollees, (age Inadequate prenatal care 11.3% NS) (n=NS) MO 1/1/1988- 12/31/1988 Slifkin, Freeman SCHIP enrollees, Income >=6y: N NR Age 12-18y Well child visit in last year 51% and Silberman aged <=18y Only 100%- (2002) NC 200% FPL ED visit in past 6 months 36% 1999-2000 (n=314) Song Medicaid Pregnancy N N NR Race 15 mos perinatal: 15-19y (2000) enrolled Disabled Black Any mental health service visit 7.4% pregnant AFDC Hispanic (Blacks: n=1,335; Hispanics: n=389; whites 10.8% women, aged 15- Other White n=302) 8.3% 45y Philadelphia, PA 1991-1993 Mean outpatient visits among those who Black 1.65 (2.04) contacted general medical sector (sd) Hispanic 1.06 (0.26) White 2.16 (1.90) (n=NS) Stevens-Simon, Pregnant Pregnancy N N NR Age 12-19y Post-partum exam within 12 weeks 71% O'Connor and adolescents, (n=212) Bassford aged 12-19y (1994) CO (NS) 69 Appendix 1.B. (continued) Reference Study Eligibility Family Required Continuous Exposure Type of Health Services Utilization Basic Health Services (Publication Population Category Income Period of Enrollment (Analytic Sample Size) Utilization Year) Eligibility Enrollment* (Duration) Szilagyi et al. New York State Income <= 230% N NR Age 12-18y During the year 72.6% (2004) SCHIP enrollees, Only FPL OR a Any preventive visit aged <=18y few NY families Most/all visits to the usual source of care 90.2% 2001-2002 purchased (n=NS) SCHIP >230% FPL Turner et al. Medicaid Pregnancy N N NR Age 15-18y Too few prenatal visits (Kessner Index) 57% (1995) enrolled (n=81) pregnant women with HIV, (age NS) NY 1985-1990 Ward Medicaid NS N N NR Age 12-19y 2 Incidence Density x 10 person- (1999) enrollees with years: asthma, aged 2- ED visit for asthma 24.4 19y Hospital Admission for asthma 5.7 Northeastern Oral steroid course 11.5 U.S. (n=61) 1/1/1993- 12/31/1994 70 Appendix 1.B. (continued) Reference Study Eligibility Family Required Continuous Exposure Type of Health Services Utilization Basic Health Services (Publication Population Category Income Period of Enrollment (Analytic Sample Size) Utilization Year) Eligibility Enrollment* (Duration) Yawn et al. Medicaid All N Y AG Age 12-18y During the year: (2001) enrollees with (10.5 months) (1.5 months) Inhaled steroid use 31% asthma, aged <= Cromoglycate use 14% 18y (n=NS) KY 7/1/1994- 6/30/1995 Zink et al. (2002) Female Medicaid NS N Y SD Age 12-19y Prescribed contraceptive use during the year 33% enrollees at high (Excluded (18 months) (n=3,338) risk for Pregnancy) pregnancy, aged 12-19y OH 1/1/1998- 6/30/1999 Zito et al. (1997) Medicaid NS N N NR Age 10-14y Average daily dose of methylphenidate (sd) 26.8 mg (14.0) enrollees, aged (n=NS) 5-14y MD 7/1/1990- 6/30/1991 CHAPTER 2 Understanding Health Care Use by Low-Income Adolescents: Do Medicaid Definitions Matter? 71 ABSTRACT Objective: To empirically examine how estimates of adolescents’ health care use vary as a function of three different, commonly used definitions of Medicaid coverage. Methods: Adolescents aged 10-19 years who were enrolled in a Rhode Island Medicaid managed care program between 07/01/2003 and 06/30/2005 were eligible for inclusion in this study (n=55,504). We compared the demographic characteristics, well care and ED use of Medicaid insured who were 1) ever enrolled (ever), 2) had a gap in enrollment (gap) and 3) were continuously enrolled (continuous). Results: The proportion of Medicaid enrolled adolescents aged 18-19 years was substantially higher using the ever group than either the gap or the continuous group definition (10.9% vs. 4.3% and 3.5% for SFY2005). In SFY2005, the adjusted relative risk ratio for well care for adolescents who were defined as Medicaid insured using the gap definition as compared to ever-enrolled Medicaid adolescents who were not included in the gap group was 1.1 (95% CI: 1.1-1.2) for females and 1.2 (95% CI: 1.1-1.2) for males. During the same year, the adjusted relative rate for ED visits for the gap vs. non- gap adolescents was 1.3 (95% CI: 1.2-1.4) for females and 1.3 (95% CI: 1.2-1.4) for males. Conclusions: Applying Medicaid definitions with more restrictive continuous enrollment requirements can result in the systematic selection of adolescents who use health services more frequently than the overall adolescent Medicaid population. When choosing a 72 73 Medicaid definition, researchers should carefully consider the insurance instability of their target population. INTRODUCTION Research demonstrates that the size of the insured and uninsured pediatric and adolescent populations in the United States during a year varies dramatically depending on the length of time that individuals are required to be continuously covered to be counted as insured.1,2 Given the insurance instability experienced by children and adolescents enrolled in Medicaid, restricting definitions of Medicaid coverage to include only individuals who were continuously enrolled for a year results in an underestimate of the number of children and adolescents enrolled at any time during the year by nearly 40%.3 While researchers and policymakers have focused on how to accurately enumerate insured and uninsured Americans, little attention has been paid to how insurance coverage definitions shape our understanding of who is served by these programs and the amount and type of health services they use. Restrictive continuous enrollment definitions may systematically select adolescents who are likely to be sicker and use health services differently than those who disenroll.4-6 Thus, using more restrictive definitions will overestimate health services utilization for the entire adolescent Medicaid population. Furthermore, measuring levels of use among continuously enrolled adolescents may mask important barriers to health care faced by those who are episodically covered. 74 75 Ongoing Medicaid program monitoring and evaluation efforts require that we have a thorough understanding of how Medicaid definitions influence research findings. We conducted this study to quantify the effect of applying three Medicaid definitions with different length of enrollment requirements on the demographic composition and health services use of Medicaid insured adolescents. METHODS Study Population Adolescents aged 10-19 years who were enrolled in a Rhode Island Medicaid managed care program at any time between 07/01/2003 and 06/30/2005 were eligible for inclusion in this study (n=60,485). During the study period, adolescents with low family incomes (< 250% federal poverty level (FPL) and <350% FPL if pregnant), foster care placement or special health care needs (SHCN) were eligible for managed care. While low-income adolescents were automatically enrolled in Medicaid managed care, foster care and SHCN adolescents could voluntarily enroll. After initial enrollment, adolescents were required to reenroll annually to maintain their Medicaid benefits. To ensure the inclusion of all health services utilization during an enrollment period, we excluded any enrollment periods during which an adolescent had another insurer or payer. The study population included 55,504 adolescents. Data Source All eligibility and claims data were obtained from the State Medicaid Research Files maintained by the Rhode Island Department of Human Services (DHS). Patient records were constructed using randomly assigned identification numbers that could be linked to enrollment data and professional and institutional claims. The Brown University Institutional Review Board approved this research. 76 77 Definition of Variables Medicaid Definitions Based on a literature review of Medicaid definitions used by adolescent health services researchers, we applied three insurance definitions with different enrollment requirements to obtain three nested adolescent study populations for each study year (Figure 2.1). The first definition, ever, included adolescents who were enrolled in Medicaid managed care at any time during the year. The second definition, gap, a subpopulation of the ever group, allowed adolescents to have no more than a single gap in enrollment of up to 45 days during a 12 month period. This is consistent with the Medicaid definition that HEDIS (Healthcare Effectiveness Data and Information Set) uses when assessing the receipt of well care.7 Continuous, the third and most restrictive definition and a subpopulation of the gap group, required that an adolescent be continuously enrolled in Medicaid for the entire study year. Demographic Variables The demographic variables included in this study were age, sex, race/ethnicity, language spoken in the home and eligibility category. Age was determined based upon either age on the first day of the study period or, if an adolescent was enrolled after this time, on the first day of enrollment. Medicaid coverage is conferred to individuals who fall into specific, federally determined aid categories.8 We grouped adolescent eligibility into the following 5 categories: (1) income only, (2) pregnancy, (3) foster care/adoption subsidy, (4) special health care needs (SHCN) and (5) multiple. The multiple eligibility category included both pregnant and low-income adolescents. If an adolescent had multiple enrollment segments with different eligibility categories during the year, the 78 eligibility category that was assigned during the longest enrollment segment was chosen. It is important to note that the eligibility category assigned by Medicaid during an enrollment period is based on a hierarchical categorization of eligibility. For example, adolescents who are pregnant and have special health care needs are assigned to a special health care needs category. Health Services Utilization In accordance with HEDIS measurement specifications, we defined an adolescent as having received a well-care visit if s/he had any of the following claims during the year: ICD-9-CM diagnosis of V20.0 through V20.2 (health supervision of an infant or child), V70.0 or V70.3 through V70.9 (general medical exam), or a Current Procedural Terminology CPT code of 99381 through 99387 or 99391 through 99397 (preventive medicine services).7,9 An emergency department (ED) visit was defined as any claim that contained a revenue code of 450 through 455 or 457 through 459 or a CPT code of 99281 through 99285 or 99288.9 If an adolescent had multiple ED claims that occurred on the same day, we assumed this constituted a single visit (approximately 1% of ED visits). As it was not clear if the Medicaid Research Files captured all ED visits that resulted in a hospitalization, we excluded ED visits that occurred on the same day as a hospitalization (approximately 4% of ED visits). Data Analysis To assess the impact of using different Medicaid definitions on the size and demographic composition of the adolescent study population and on the receipt of well care and ED visits during the year, we calculated proportions and rates and corresponding 95 percent confidence intervals. Medicaid enrollment duration was calculated as the total 79 number of days that an individual was insured by Medicaid. For each year, multivariable binomial regression analyses were used to estimate the relative risk of receiving well care for Medicaid definitions and multivariable negative binomial regression analyses were used to estimate adjusted incidence rate ratios of ED utilization for the Medicaid definitions. It is important to note that in the multivariable analyses only, the Medicaid insurance group definitions were mutually exclusive. For example, the gap adolescents were compared to adolescents who were ever Medicaid enrolled and who were not included in the gap group (non-gap). All analyses were conducted separately for SFY2004 and SFY2005 using STATA version 9.0 SE (Stata Corp, College Station, TX). RESULTS Demographic Characteristics by Medicaid Definition The number of Medicaid insured adolescents varied substantially by Medicaid definition during SFY2004 and SFY2005 (Table 2.1). Applying the continuous definition excluded nearly half of the adolescents who were ever enrolled during each of the two study years (47,2006 vs. 25,336 for SFY2004 and 47,452 vs. 28,848 for SFY2005). The proportion of Medicaid enrolled adolescents aged 18-19 years was substantially higher in the ever group than either the gap or the continuous groups (11.3% vs. 4.1% and 3.2%, 10.9% vs. 4.3% and 3.5% for SFY2004 and SFY2005, respectively). In contrast, we found no substantial differences in the distribution of sex, race/ethnicity and language spoken at home as a function of the three Medicaid definitions. Health Services Use by Medicaid Definition: Well Care and Emergency Department Visits Regardless of age, sex, race/ethnicity, language spoken at home or eligibility category, adolescents in the ever group were less likely to receive well care during the year as compared to adolescents in the gap or continuous groups (Table 2.2). In SFY2005, 36.9% of ever enrolled adolescents received well care as compared to 46.0% of gap and 46.6% of continuous adolescents. Overall, the rate of ED visits did not vary substantially for adolescents by Medicaid definition during the two study years (360.0 per 1,000 person-years to 370.1 80 81 per 1,000 person-years) (Table 2.3). However, we did observe differences in ED visit rates by Medicaid definition for age, sex and eligibility category. For both years, the ED visit rates for older, ever enrolled adolescents were substantially lower than that of same- aged gap adolescents (663.6 per 1,000 person-years vs. 838.1 per 1,000 person-years and 727.3 per 1,000 person-years vs. 886.5 per 1,000 person-years for SFY2004 and SFY2005, respectively). We conducted binomial and negative binomial multivariable regression analyses to examine associations between Medicaid definitions and the receipt of well care and ED visits. As results were similar for the gap and the continuous Medicaid definitions, analyses are only presented for the comparison of the gap definition and adolescents who were ever Medicaid enrolled and who were not included in the gap group (non-gap) (Table 2.4). In SFY2005, the adjusted relative risk ratio for well care using the gap definition as compared to non-gap was 1.1 (95% CI: 1.1-1.2) for females and 1.2 (95% CI: 1.1-1.2) for males. We also found that gap enrolled females and males had a higher rate of ED visits (SFY2005: 1.3 (95% CI: 1.2-1.4) and 1.3 (95% CI: 1.2-1.4), respectively). DISCUSSION The objective of this study was to empirically examine if Medicaid definitions contribute to variations in estimates of adolescent health services use. For both study years, applying more restrictive Medicaid definitions (continuous and gap) resulted in substantially smaller proportions of older adolescents being defined as Medicaid insured and higher rates of well-care and ED use than applying a less restrictive Medicaid definition. Using both the continuous and the gap Medicaid definitions limited the adolescent study population to slightly more than half of the size of those who were ever enrolled. Insurance instability during the year was common among adolescents and is consistent with reported estimates of Medicaid and SCHIP (State Children’s Insurance Program) enrollment patterns throughout the United States.3,10,11 One of the greatest sources of Medicaid enrollment instability resulted from older adolescents aging out of our study. In a majority of states, similar programmatic instability occurs when income-only eligible adolescents lose their Medicaid coverage on their nineteenth birthday.12 Given the enrollment instability experienced by 18 and 19 year-olds in this study, it is not surprising that applying different enrollment requirements led to substantial volatility in the estimates of their well care receipt and ED use. As Medicaid enrollment instability is common throughout the United States, concerns have been raised that using more restrictive definitions may produce estimates of health services utilization that do not reflect the health care experience of the pediatric 82 83 and adolescent Medicaid population.13 Our results demonstrate that applying more restrictive Medicaid definitions can overestimate the well-care receipt and ED rates of Medicaid insured adolescents because they do not reflect the experience of adolescents who are censored. Similar results were found by Cooper and colleagues.5 Researchers and policymakers often evaluate the Medicaid program with data sets that disproportionately weight their study populations with continuously enrolled adolescents.7,13-15 Such data sources can provide an assessment of how Medicaid performs when it has had adequate time to assume responsibility for it’s enrollees; however, using them to describe the health care experience for the adolescent Medicaid population may result in biased estimates of health services use and may conceal important barriers to health care.13 An important limitation of our study is that the population included only adolescents enrolled in Medicaid managed care in a single state. There is considerable variation in the structure and benefit generosity of the Medicaid programs and in the stability of Medicaid enrollment throughout the United States.3,11 Therefore, the generalizability of our results may be limited to states with Medicaid programs and eligibility criteria that are similar to those in RI. While we do not suggest that a single Medicaid definition should be used to evaluate health services use by adolescents enrolled in Medicaid, we recommend that researchers give careful consideration to the insurance instability of their target population and the influence that this instability has on estimates of use. To facilitate cross-study comparisons, future research should also include clear, concise, 84 detailed descriptions of Medicaid and SCHIP insurance definitions. REFERENCES 1. Olson LM, Tang SF, Newacheck PW. Children in the United States with discontinuous health insurance coverage. N Engl J Med. 2005;353:382-391. 2. Tang SF, Olson LM, Yudkowsky BK. Uninsured children: how we count matters. Pediatrics. 2003;112:e168-73. 3. Fairbrother GL, Emerson HP, Partridge L. How stable is Medicaid coverage for children? Health Aff (Millwood). 2007;26:520-528. 4. Berman S, Bondy J, Lezotte D, Stone B, Byrns PJ. The influence of having an assigned Medicaid primary care physician on utilization of otitis media-related services. Pediatrics. 1999;104:1192-1197. 5. Cooper WO, Arbogast PG, Hickson GB, Daugherty JR, Ray WA. Gaps in enrollment from a Medicaid managed care program: effects on emergency department visits and hospitalizations for children with asthma. Med Care. 2005;43:718-725. 6. Stein RE, Shenkman E, Wegener DH, Silver EJ. Health of children in title XXI: should we worry? Pediatrics. 2003;112:e112-8. 7. National Committee for Quality Assurance. HEDIS 3.0/1998: Health Plan Employer Data and Information Set. Washington, DC. National Committee for Quality Assurance; 1997. 8. Schneider A, Elias R, Rousseau D, Wachino V. The Medicaid Resource Book. Washington, DC: The Henry J. Kaiser Family Foundation; 2002. 85 86 9. American Medical Association. CPT 2006: Current Procedural Terminology (Standard Edition). Chicago, IL: American Medical Association; 2006. 10. Sommers BD. From Medicaid to uninsured: drop-out among children in public insurance programs. Health Serv Res. 2005;40:59-78. 11. Summer L, Mann C. Instability of Public Health Insurance Coverage for Children and Their Families: Causes, Consequences and Remedies. The Commonwealth Fund. 2006 12. Fox HB, Limb SJ, McManus MA. The Public Health Insurance Cliff for Older Adolescents [Intercenter Strategies website]. April 2007. Available at: http://www.incenterstrategies.org/jan07/factsheet4.pdf. Accessed July 4, 2008. 13. U.S. General Accounting Office. Medicaid and SCHIP: States Use Varying Approaches to Monitor Children's Access to Care, GAO-03-222. Washington, DC: General Accounting Office, January 2003. 14. Newacheck PW, Brindis CD, Cart CU, Marchi K, Irwin CE. Adolescent health insurance coverage: recent changes and access to care. Pediatrics. 1999;104:195- 202. 15. Newacheck PW, Park MJ, Brindis CD, Biehl M, Irwin CEJ. Trends in private and public health insurance for adolescents. JAMA. 2004;291:1231-1237. 87 Figure 2.1. Adolescent Medicaid study populations identified by three enrollment definitions used by health services researchers. Ever Gap Continuous Note: The Ever definition includes adolescents enrolled in Medicaid at any time. The Gap definition allows adolescents to have no more than a single gap in enrollment of up to 45 days during a 12 month period. Continuous, the third and most restrictive definition, requires that an adolescent be continuously enrolled in Medicaid for the entire study year. 88 Table 2.1. Demographic Characteristics of Adolescents by Medicaid Insurance Definition*, Rhode Island, 7/1/2003- 6/30/2005 % (95% CI) Demographic 7/1/2003-6/30/2004 7/1/2004-6/30/2005 Characteristic Ever Gap Continuous Ever Gap Continuous (n=47,206) (n=27,721) (n=25,336) (n=47,452) (n=31,420) (n=28,848) Age (years)† 10-14 62.2 65.8 66.3 62.0 64.4 64.7 (61.8-62.6) (65.3-66.4) (65.7-66.9) (61.5-62.4) (63.9-65.0) (64.1-65.2) 15-17 26.5 30.1 30.5 27.1 31.3 31.8 (26.1-26.9) (29.6-30.6) (29.9-31.1) (26.7-27.5) (30.7-31.8) (31.3-32.4) 18-19 11.3 4.1 3.2 10.9 4.3 3.5 (11.0-11.6) (3.9-4.3) (3.0-3.4) (10.6-11.2) (4.1-4.5) (3.3-3.7) Sex Male 49.8 49.5 49.5 50.0 50.6 50.8 (49.4-50.3) (48.9-50.1) (48.9-50.1) (49.5-50.4) (50.0-51.1) (50.2-51.3) Female 50.2 50.5 50.5 50.1 49.4 49.2 (49.7-50.6) (50.0-51.1) (49.9-51.2) (49.6-50.5) (48.9-50.0) (48.7-49.8) 89 Table 2.1. (continued) % (95% CI) Demographic 7/1/2003-6/30/2004 7/1/2004-6/30/2005 Characteristic Ever Gap Continuous Ever Gap Continuous (n=47,206) (n=27,721) (n=25,336) (n=47,452) (n=31,420) (n=28,848) Race/Ethnicity Non-Hispanic White 48.3 46.8 46.9 48.0 47.2 47.2 (47.8-48.8) (46.2-47.5) (46.2-47.6) (47.5-48.5) (46.6-47.9) (46.6-47.9) Non-Hispanic Black 14.2 14.1 14.3 14.1 14.3 14.3 (13.8-14.5) (13.7-14.6) (13.8-14.8) (13.7-14.5) (13.9-14.8) (13.9-14.8) Hispanic 33.0 34.2 33.9 33.7 34.2 34.2 (32.5-33.5) (33.5-34.8) (33.2-34.5) (33.2-34.2) (33.7-34.8) (33.6-34.8) American Indian/Asian/Pacific 4.6 4.9 5.0 4.2 4.2 4.3 Islander (4.3-4.8) (4.6-5.2) (4.7-5.3) (4.0-4.4) (4.0-4.5) (4.0-4.5) Missing 10,642 5,559 4,972 11,248 6,497 5,784 Language Spoken at Home English 77.4 75.2 75.2 76.9 75.7 75.7 (77.0-77.7) (74.7-75.7) (74.6-75.7) (76.6-77.3) (75.2-76.2) (75.2-76.2) Non-English 22.7 24.8 24.9 23.1 24.3 24.3 (22.3-23.0) (24.3-25.3) (24.3-25.4) (22.7-23.4) (23.8-24.8) (23.8-24.8) 90 Table 2.1. (continued) % (95% CI) Demographic 7/1/2003-6/30/2004 7/1/2004-6/30/2005 Characteristic Ever Gap Continuous Ever Gap Continuous (n=47,206) (n=27,721) (n=25,336) (n=47,452) (n=31,420) (n=28,848) Eligibility Category‡ Income Only 81.0 87.1 87.1 80.8 79.8 79.3 (80.6-81.3) (86.7-87.5) (86.7-87.5) (80.5-81.2) (79.4-80.3) (78.8-79.8) Pregnancy 0.5 0.2 0.2 0.5 0.2 0.2 (0.5-0.6) (0.2-0.3) (0.1-0.3) (0.4-0.6) (0.2-0.3) (0.1-0.2) SHCN 11.0 4.7 4.6 11.3 12.3 12.8 (10.7-11.3) (4.4-4.9) (4.4-4.9) (11.0-11.6) (12.0-12.7) (12.4-13.1) Foster Care/Adoption 6.5 7.8 7.9 6.5 7.4 7.6 Subsidy (6.2-6.7) (7.5-8.1) (7.6-8.3) (6.2-6.7) (7.1-7.7) (7.3-7.9) Multiple 1.1 0.2 0.2 0.9 0.2 0.2 (1.0-1.2) (0.2-0.3) (0.1-0.2) (0.8-1.0) (0.2-0.3) (0.1-0.2) *Medicaid insurance definitions: Continuous includes individuals continuously enrolled for the entire year; Gap includes individuals who had no more than a single gap in enrollment of up to 45 days during the year; Ever includes individuals who were enrolled for at least one day during the year. †Age at the beginning of the study year or the first day of enrollment. ‡Medicaid managed care enrollment eligibility in Rhode Island: Foster care enrollment effective 12/1/2000; Children with special health care needs (SHCN) were not eligible until 2003; Multiple includes such eligibility categories as income only and pregnancy. Abbreviation: CI, Confidence Interval. 91 Table 2.2. The Proportion of Adolescents who Received Well Care During the Year by Medicaid Insurance Definition*, Rhode Island, 7/1/2003-6/30/2005 Adolescents with Well Care, % (95% CI) Demographic 7/1/2003-6/30/2004 7/1/2004-6/30/2005 Characteristic Ever Gap Continuous Ever Gap Continuous (n=47,206) (n=27,721) (n=25,336) (n=47,452) (n=31,420) (n=28,848) 35.1 47.1 47.8 36.9 46.0 46.6 Total (34.6-35.5) (46.5-47.7) (47.2-48.4) (36.5-37.3) (45.5-46.6) (46.0-47.1) Age (years)† 10-14 39.8 50.9 51.4 41.7 50.5 51.0 (39.2-40.4) (50.2-51.7) (50.6-52.2) (41.1-42.3) (49.8-51.2) (50.3-51.7) 15-17 32.7 41.1 41.8 34.3 39.6 39.8 (31.8-33.5) (40.1-42.2) (40.7-42.9) (33.5-35.1) (38.7-40.6) (38.8-40.8) 18-19 14.7 29.2 30.3 16.0 25.7 25.7 (13.7-15.6) (26.5-31.8) (27.2-33.5) (15.0-17.0) (23.4-28.1) (23.0-28.4) Sex Male 33.2 44.9 45.6 35.2 43.8 44.3 (32.6-33.8) (44.1-45.8) (44.7-46.4) (34.6-35.8) (43.1-44.6) (43.5-45.1) Female 36.9 49.2 50.0 38.6 48.3 48.9 (36.3-37.5) (48.4-50.1) (49.1-50.9) (38.0-39.2) (47.5-49.1) (48.1-49.7) 92 Table 2.2. (continued) Adolescents with Well Care, % (95% CI) Demographic 7/1/2003-6/30/2004 7/1/2004-6/30/2005 Characteristic Ever Gap Continuous Ever Gap Continuous (n=47,206) (n=27,721) (n=25,336) (n=47,452) (n=31,420) (n=28,848) Race/Ethnicity Non-Hispanic White 34.1 45.9 46.5 35.6 44.1 44.4 (33.4-34.8) (45.0-46.9) (45.5-47.5) (34.9-36.3) (43.2-45.0) (43.5-45.4) Non-Hispanic Black 33.2 43.2 43.8 35.1 43.1 43.5 (31.9-34.4) (41.4-44.9) (42.0-45.7) (33.8-36.4) (41.5-44.7) (41.8-45.2) Hispanic 39.6 51.6 52.4 41.9 50.7 51.4 (38.7-40.5) (50.5-52.7) (51.2-53.6) (41.0-42.8) (49.7-51.8) (50.3-52.6) American Indian/Asian/Pacific 30.6 39.8 40.6 32.2 39.4 39.9 Islander (28.4-32.8) (36.8-42.7) (37.5-43.6) (29.9-34.6) (36.5-42.4) (36.8-43.0) Language Spoken at Home English 33.5 45.9 46.6 35.3 44.4 44.8 (33.0-34.0) (45.2-46.5) (45.9-47.3) (34.8-35.8) (43.8-45.1) (44.1-45.4) Non-English 40.3 50.9 51.5 42.3 51.0 52.1 (39.4-41.2) (49.7-52.0) (50.3-52.8) (41.3-43.2) (49.9-52.2) (50.9-53.2) 93 Table 2.2. (continued) Adolescents with Well Care, % (95% CI) Demographic Characteristic 7/1/2003-6/30/2004 7/1/2004-6/30/2005 Ever Gap Continuous Ever Gap Continuous (n=47,206) (n=27,721) (n=25,336) (n=47,452) (n=31,420) (n=28,848) Eligibility Category‡ Income Only 39.5 50.4 51.2 40.6 51.0 51.8 (39.0-39.9) (49.7-51.0) (50.5-51.8) (40.1-41.0) (50.3-51.6) (51.1-52.4) Pregnancy 8.5 17.9 22.5 10.6 20.3 18.8 (5.0-12.0) (8.5-27.3) (10.3-34.6) (6.7-14.6) (10.6-30.0) (7.3-30.2) SHCN 13.3 19.0 18.4 19.2 23.0 23.2 (12.4-14.2) (16.8-21.1) (16.2-20.6) (18.1-20.3) (21.6-24.3) (21.8-24.5) Foster Care/ Adoption Subsidy 24.2 29.4 29.2 28.1 33.0 32.7 (22.7-25.7) (27.5-31.3) (27.2-31.2) (26.5-29.6) (31.1-34.9) (30.7-34.6) Multiple† 4.6 11.7 15.8 8.2 20.3 25.0 (2.8-6.4) (3.3-20.0) (3.6-27.9) (5.6-10.8) (10.9-29.7) (12.3-37.7) *Medicaid insurance definitions: Continuous includes individuals continuously enrolled for the entire year; Gap includes individuals who had no more than a single gap in enrollment of up to 45 days during the year; Ever includes individuals who were enrolled for at least one day during the year. †Age at the beginning of the study year or the first day of enrollment. ‡Medicaid managed care enrollment eligibility in Rhode Island: Foster care enrollment effective 12/1/2000; Children with special health care needs (SHCN) were not eligible until 2003; Multiple includes such eligibility categories as income only and pregnancy. Abbreviation: CI, Confidence Interval. 94 Table 2.3. Emergency Department Utilization by Adolescents by Medicaid Insurance Definition*, Rhode Island, 7/1/2003- 6/30/2005 Emergency Department Visit Rate per 1,000 Member-Years (95% CI) Demographic 7/1/2003-6/30/2004 7/1/2004-6/30/2005 Characteristic Ever Gap Continuous Ever Gap Continuous (n=47,206) (n=27,721) (n=25,336) (n=47,452) (n=31,420) (n=28,848) Total 360.0 373.7 370.1 363.5 369.4 366.1 (349.8-370.3) (363.0-384.4) (359.1-381.1) (353.5-373.4) (359.1-379.6) (355.5-376.7) Age (years)† 10-14 275.2 299.5 302.1 272.7 298.3 299.2 (264.6-285.8) (288.9-310.1) (291.1-313.1) (263.3-282.1) (287.9-308.7) (288.4-310.0) 15-17 429.5 473.0 463.5 424.6 444.6 446.3 (410.5-448.5) (449.8-496.2) (439.7-487.3) (406.4-442.7) (424.4-464.9) (425.3-467.4) 18-19 663.6 838.1 887.6 727.3 886.5 870.6 (611.5-715.7) (745.3-930.9) (773.3-1,001.9) (669.7-784.9) (788.1-984.8) (757.4-983.7) Sex Male 287.9 316.5 315.7 293.8 306.0 309.3 (276.3-299.6) (304.0-328.9) (302.8-328.7) (281.8-305.8) (294.1-317.9) (296.8-321.8) Female 431.6 429.7 423.3 433.0 434.2 424.7 (414.9-448.4) (412.5-446.9) (405.6-441.1) (417.2-448.9) (417.5-450.9) (407.6-441.8) 95 Table 2.3. (continued) Emergency Department Visit Rate per 1,000 Member-Years (95% CI) Demographic 7/1/2003-6/30/2004 7/1/2004-6/30/2005 Characteristic Ever Gap Continuous Ever Gap Continuous (n=47,206) (n=27,721) (n=25,336) (n=47,452) (n=31,420) (n=28,848) Race/Ethnicity Non-Hispanic White 388.8 414.1 408.3 399.8 405.0 401.7 (371.7-405.9) (395.5-432.7) (389.3-427.4) (382.2-417.4) (386.6-423.3) (382.6-420.8) Non-Hispanic Black 353.2 365.9 365.1 384.2 392.2 387.7 (325.4-381.0) (332.7-399.0) (330.5-399.6) (354.3-414.1) (361.7-422.7) (357.4-417.9) Hispanic 388.2 389.4 381.5 378.0 380.7 377.9 (365.5-410.9) (368.6-410.1) (360.0-402.9) (359.1-396.8) (361.1-400.2) (357.9-397.9) American Indian/Asian/ 173.7 174.6 169.3 205.3 182.0 178.8 Pacific Islander (141.9-205.5) (140.0-209.1) (137.4-201.2) (154.5-256.1) (148.1-216.0) (144.0-213.6) Language Spoken at Home English 379.2 398.9 395.3 388.0 393.7 390.1 (367.2-391.1) (385.9-411.9) (381.9-408.7) (376.0-400.0) (381.2-406.1) (377.3-403.0) Non-English 294.6 297.3 293.9 281.8 293.5 291.3 (275.3-313.9) (280.2-314.5) (276.2-311.7) (265.6-297.9) (277.1-310.0) (274.4-308.1) 96 Table 2.3. (continued) Emergency Department Visit Rate per 1,000 Member-Years (95% CI) Demographic 7/1/2003-6/30/2004 7/1/2004-6/30/2005 Characteristic Ever Gap Continuous Ever Gap Continuous (n=47,206) (n=27,721) (n=25,336) (n=47,452) (n=31,420) (n=28,848) Eligibility Category‡ Income Only 339.4 361.1 361.3 332.4 356.6 357.4 (329.0-349.7) (350.4-371.8) (350.1-372.5) (322.7-342.1) (346.0-367.3) (346.3-368.5) Pregnancy 816.1 633.9 672.1 711.4 712.3 708.8 (494.7-1,137.4) (342.2-925.6) (329.0-1,015.2) (485.7-937.1) (469.7-954.9) (409.4-1,008.3) SHCN 398.7 546.5 512.2 458.2 412.4 400.9 (362.8-434.7) (468.8-624.2) (433.2-591.2) (417.9-498.6) (374.4-450.4) (362.3-439.5) Foster Care/ Adoption 353.0 362.7 349.4 386.6 370.7 360.8 Subsidy (316.0-390.1) (319.7-405.7) (305.3-393.4) (347.0-426.2) (332.3-409.1) (321.7-399.9) Multiple† 1,350.3 1,819.9 1,812.1 1,601.9 2,061.9 1,751.2 (1,064.7- (1,362.8- (1,227.0- (1,291.8- (1,484.9- (1,159.3- 1,635.9) 2,277.0) 2,397.1) 1,912.0) 2,638.8) 2,343.1) *Medicaid insurance definitions: Continuous includes individuals continuously enrolled for the entire year; Gap includes individuals who had no more than a single gap in enrollment of up to 45 days during the year; Ever includes individuals who were enrolled for at least one day during the year. †Age at the beginning of the study year or the first day of enrollment. ‡Medicaid managed care enrollment eligibility in Rhode Island: Foster care enrollment effective 12/1/2000; Children with special health care needs (SHCN) were not eligible until 2003; Multiple includes such eligibility categories as income only and pregnancy. Abbreviation: CI, Confidence Interval. Note: Rate = (total visits while enrolled in Medicaid during the year / total number of days enrolled in Medicaid during the year / 365.25) x 1,000 97 Table 2.4. Crude and Adjusted Relative Risks for Well Care and Incidence Rate Ratios for Emergency Department Visits for Medicaid Insured Adolescents, Rhode Island, 7/1/2003-6/30/2005 SFY2004 SFY2005 Medicaid Adjusted for Adjusted for Insurance Duration of Adjusted for Selected Duration of Adjusted for Selected Definition Medicaid Demographic Medicaid Demographic Enrollment Characteristics and Duration Enrollment Characteristics and Duration Crude Only of Medicaid Enrollment Crude Only of Medicaid Enrollment Females Males Females Males Adjusted Adjusted Adjusted Adjusted Well Care RR RR RR† RR† RR RR RR† RR† (95% CI) (95% CI) (95% CI) (95% CI) (95% CI) (95% CI) (95% CI) (95% CI) Non-Gap 1 1 1 1 1 1 1 1 2.6 1.3 1.1 1.1 2.4 1.2 1.1 1.2 Gap (2.5-2.7) (1.3-1.4) (1.0-1.1) (1.0-1.1) (2.3-2.5) (1.1-1.2) (1.1-1.2) (1.1-1.2) Females Males Females Males Adjusted Adjusted Adjusted Adjusted ED Visits IRR IRR IRR† IRR† IRR IRR IRR† IRR† (95% CI) (95% CI) (95% CI) (95% CI) (95% CI) (95% CI) (95% CI) (95% CI) Non-Gap 1 1 1 1 1 1 1.1 1.3 1.1 1.0 1.3 1.3 Gap (1.0-1.1) (1.2-1.4) (1.0-1.2) (1.0-1.1) (1.2-1.4) (1.2-1.4) *Medicaid enrollment definitions: Gap includes adolescents with no more than a single gap in enrollment of up to 45 days during a 12 month period. The non-Gap definition includes adolescents who were enrolled in Medicaid for at least one day and who had more than a single gap in enrollment of 45 days during a 12 month period. SFY2004: Non-Gap n=19,485, Gap n=27,721. SFY2005: Non-Gap n=16,212, Continuous n=31,240. †Adjusted for age, eligibility category and duration of Medicaid enrollment (days). Abbreviations: RR indicates risk ratio, CI indicates confidence interval, IRR indicates incidence rate ratio; ED indicates Emergency Department. Note: Emergency department visit rates include person-time in their calculation and, by definition, adjust for person time enrolled in Medicaid. CHAPTER 3 Health Care Access and Emergency Department Utilization by Low-Income Adolescents in the United States 98 ABSTRACT OBJECTIVE. To quantify the association of three broad measures of health care access (insurance, having a usual source of care and ambulatory care use) on emergency department (ED) utilization by low-income adolescents. METHODS. Adolescents aged 10 through 17 years whose households participated in the Medical Expenditure Panel Survey-Household Component in 2003 or 2005, with family incomes less than 200 percent of the federal poverty level were included in this study. Data were obtained via interview with a parent or knowledgeable adult. Logistic regression analyses were conducted to examine predictors of annual ED use. All analyses were stratified by gender. RESULTS. The annual ED visit rate for females and males was 1,534 per 10,000 adolescents and 1,453 per 10,000 adolescents, respectively. As compared to females with full year private insurance, the odds of having any ED use was 3.2 (95% CI: 1.8-5.7) for females with full-year public insurance, 5.9 (95% CI: 2.9-12.0) for females with both private and public insurance, 2.1 (95% CI: 1.1-4.0) for females who were uninsured for part of the year and 1.8 (95% CI: 0.9-3.7) for females who were uninsured for the full year. Insurance coverage was not associated with ED use among males. Both males and females who had at least one ambulatory care visit during the year had higher ED visit rates than adolescents who did not use ambulatory care (females: 1,932 vs. 903 per 10,000; males: 1,861 vs. 887 per 10,000). Within stratum of the three health indicators 99 100 (health status, SHCN (special health care needs), asthma) ED and ambulatory care utilization patterns varied substantially. CONCLUSIONS. Our study demonstrates that emergency department utilization by low-income adolescents differs substantially by gender. Of the three health care access measures studied, none were associated with ED utilization by males and insurance coverage was associated with ED utilization only for females. Our research suggests that improving the current model of adolescent health care will require addressing gender- specific health care needs and care seeking behaviors. INTRODUCTION In the United States in 2006, children and adolescents visited the emergency department (ED) 26.3 million times.1 On average, approximately 72,000 pediatric and adolescent ED visits were made each day. Adolescents’ rates of nonurgent, emergency department visits are higher than those of any other age group.2 Over half of their nonurgent ED visits could be treated in other, less expensive outpatient settings that are better prepared to address their unique, ongoing health care needs.3 Adolescents’ health care needs differ from younger children and adults and are consistent with the tremendous physical changes that they experience and the unhealthy habits and behaviors that some initiate during this time. Although adolescents are generally assumed to be healthy, one in five is diagnosed with at least one serious health problem such as asthma or depression that requires routine monitoring that is not generally available through the ED.4,5 At greatest risk for emergency department utilization are adolescents in families with low incomes.6 Approximately 40 percent of all adolescents are in poor and near- poor families and this proportion is increasing.7 According to the Society for Adolescent Medicine, “Poverty is the single most important factor affecting the health of adolescents”.5 Adolescents in low-income families are more likely to be in fair or poor health, have chronic health conditions and encounter substantial barriers to health care than their middle or higher income counterparts.4,6-9 In a U.S. study that included children 101 102 and adolescents, researchers reported that the odds of visiting the ED for children whose family incomes were less than 100 percent of federal poverty level (FPL) were two times that of children whose family incomes were at least 400 percent FPL. 6 During the last twelve years, significant program and policy changes including Medicaid expansions and the creation of SCHIP have been implemented that provide adolescents in low-income families with unprecedented access to primary, preventive health care.10 Despite efforts to expand insurance coverage to adolescents in low-income families, access remains a concern. Some researchers have postulated that limited access to health care drives low-income adolescents’ ED utilization3; however, very little research has been conducted that examines how access to regular medical care affects ED use in this population after the implementation of SCHIP and states’ Medicaid expansions.11,12 One study measured the impact of SCHIP on adolescents’ ED use in North Carolina and found that insurance did not alter whether they made an ED visit during a 6-month period.12 However, insurance coverage did reduce their reliance on the ED as both the only source of acute care and as their only contact with the health care system. This study raises important questions about the association between insurance coverage and ED use; however, it is unclear if the results extend to privately insured and Medicaid insured adolescents or to low-income adolescents from other states. In a second national study, Brousseau and colleagues (2007) reported that adolescents who did not experience a barrier to either getting care or a referral to a specialist had substantially lower rates of nonurgent ED use than adolescents who experienced these barriers.11 On the other hand, they found that getting a health care appointment or help by phone as soon as they wanted did not significantly impact adolescents’ urgent or nonurgent ED 103 use. This finding indicates that further research is needed to understand the association between barriers to health care and adolescent ED use. In addition, neither of the two studies examined whether the association between access to care and ED use varied by gender.11,12 During adolescence, gender-specific differences in morbidity and ED utilization emerge and the impact of access to health care on ED use may also differ for male and female adolescents; however, few studies have focused on gender differences in ED utilization in this population. 1,13-15 Improving the quality of health services delivered to vulnerable adolescent populations is currently receiving national attention.13,16 Understanding why adolescent females and males seek care in settings that are not designed to address the full spectrum of their health care needs in a cost-effective manner is a critical first step towards creating a new, high quality, adolescent care model that can be sustained even during an economic downturn. We conducted this study to extend the current research on adolescent ED utilization. Although it is assumed that those with a usual source of care (medical home) will have lower ED use, the impact of a usual source of care on ED utilization specifically in adolescents is largely unknown. The value of expanding insurance coverage to low-income adolescents depends on whether they utilize less expensive and more comprehensive ambulatory care in lieu of ED visits for routine care; yet, no study has specifically examined whether low-income adolescents who make primary care or other ambulatory care visits have lower ED utilization. Using national data from the 2003 and 2005 Medical Expenditure Panel Survey, we evaluated the association between three broad measures of health care access (insurance coverage, having a usual source of care (USC) and ambulatory care use) and emergency department utilization by low- 104 income female and male adolescents. As a secondary objective, we also examined the effect of sociodemographic characteristics and health status indicators on ED use by low- income female and male adolescents. METHODS Data Source The Medical Expenditure Panel Survey (MEPS) is an ongoing, national household survey that provides detailed information on sociodemographic characteristics, health insurance coverage, health status, health conditions, health care access and utilization data for the United States, civilian, non-institutionalized population.17 It is conducted by the Agency for Healthcare Research and Quality and is comprised of two components: the Household Component (MEPS-HC) and the Insurance Component (MEPS-IC). For the purposes of this study, we analyzed data from the MEPS-HC. The MEPS-HC uses an overlapping panel design (Figure 3.1).17 Each year, a new panel of households is selected from a subsample of respondents to the previous year’s National Health Information Survey (NHIS). The MEPS-HC oversamples black, Hispanic, Asian, and low-income (<200 percent of federal poverty level) households. Each household is interviewed during five rounds that span two calendar years. Two or three household interviews are conducted each year. Sociodemographic, insurance and health services utilization data are collected during each interview for each household member. In addition, health indicators and usual source of care (USC) information are collected once per year. All information for each household member is reported by a parent or other knowledgeable adult household respondent using computer assisted personal 105 106 interviewing technology and is supplemented by data provided by a sample of their medical providers. The overall response rate for the MEPS-HC was 64.5 percent in 2003 and 61.3 percent in 2005. Study Population To address the study goals, adolescents aged 10 through 17 years whose households participated in the MEPS-HC in 2003 or 2005, from families with incomes less than 200 percent of the federal poverty level (FPL) and for whom insurance and health services utilization data were collected for the entire study year were eligible for inclusion in this study. Although the World Health Organization defines adolescents as 10 to 19 year-olds, we limited the age of our adolescent study population to individuals aged 10 through 17 years because the MEPS only collects relevant health indicator and usual source of care information for individuals under 18 years of age.17,18 We excluded 57 adolescents who left or who were not part of a respondent household for the entire study period (n=41), died (n=3) or were institutionalized (n=13) during the study period because a full year of data was not collected for them. To ensure that an adequate sample of low-income adolescents was obtained, we included individuals from two survey panels (Figure 3.1). Our study population was comprised of 4,369 adolescents (2,253 in 2003 and 2,116 in 2005) who were followed for one year. Study Variables Emergency Department Utilization Emergency department (ED) utilization was defined as the total number of emergency department visits reported during multiple rounds of interviews during each 107 year of follow-up. We also dichotomized emergency department utilization to reflect those with any ED use during the year. Access to and Use of Health Care Three main independent variables were used to measure access to health care. The first, insurance coverage, is an indicator of financial access to health care. Because of the volatility of health insurance coverage, and because we had information on health insurance on a monthly basis, adolescent insurance coverage was classified into the following five categories reflecting the pattern of coverage: full-year private, full-year public, both public and private, part-year uninsured, full-year uninsured. Adolescents who were covered by private sources for the entire year were defined as full-year private. Adolescents who were insured by TRICARE (a health care program for active duty service members), Medicare, Medicaid, SCHIP (State Children’s Health Insurance Program) or other public hospital/physician programs for the entire year were classified as full-year public. Adolescents who had both private and public insurance during the year and who were insured for the entire year were categorized as both private and public insurance. We categorized adolescents who were uninsured for as many as eleven months during the year as part-year uninsured. Adolescents who were uninsured for all twelve months were classified as full-year uninsured. Our second independent variable, usual source of care (USC), measured an adolescent’s access to a primary care provider. Access to a USC was assessed by the following survey items: (1) whether a USC was reported and (2) the number of barriers to accessing health care that were identified for adolescents who had a USC. Adolescents were defined as having a USC if they received sick care or health advice from a provider 108 or place of care other than the emergency department. Barriers to health care were identified by five provider access questions and included longer travel time to the USC (>30 minutes), difficulty getting to the USC, difficulty contacting the USC during regular business hours, no night/weekend office hours at the USC and difficulty contacting the USC after regular hours for urgent medical needs (Table 3.1). The total number of barriers was summed. We created a composite variable and categorized the USC as follows: (1) USC, no barriers to health care, (2) USC, one barrier to health care, (3) USC, two to five barriers to health care and (4) no USC. To further characterize the primary care provider relationship in this population, we intended to examine the following USC characteristics: (1) first contact care, (2) longitudinal care and (3) coordination of care. However, since nearly all adolescents with a USC were reported to have all three characteristics, we did not include these factors in our analyses. Ambulatory care use, the third access variable, includes any outpatient health care visit that did not occur in the emergency department and is measured by the total number of visits that took place in office-based settings, clinics and hospital outpatient departments during the year as well as by an indicator variable (yes vs. no). Sociodemographic Characteristics and Health Status Based on previous research, we examined age, sex, race/ethnicity, interview language, region, residence, family income and three health indicators (health status, special health care needs, and asthma) as determinants of ED utilization. Prior research on adolescent ED use has shown that older age is associated with higher ED utilization.19 For younger adolescents, males have higher ED rates than females; however, for older 109 adolescents, females have higher ED rates than males. In addition, adolescents who have asthma are more likely to use the ED than those who do not have asthma. 20 In pediatric research that included adolescents, black race, urban residence, and worse health status were associated with higher ED use.6,8,21-23 Residence in the Midwest is associated with using the ED as a usual source of sick care and may also be associated with increased overall ED utilization.8 In addition, we hypothesized that adolescents who were in non-English speaking households would be more likely to experience barriers to primary care and therefore may be more likely to use the ED than adolescents in English speaking households. Age was determined at the time of the first interview and, based on the recommendations of the American Medical Association’s Guidelines for Adolescent Preventive Services (GAPS), was categorized as 10 to 14 years and 15 to 17.24 Race/ethnicity was defined as non-Hispanic white, non-Hispanic black, Hispanic and other. Region was classified as Northeast, Midwest, South and West. Residence was categorized as urban or rural and is based on the application of the United States Office of Management and Budget standards to the Census.17 Income was constructed by dividing family income by the applicable poverty line and was categorized based on percentages (0% - <100% and 100% - <200% federal poverty level (FPL)).17 Poverty statistics were developed by the Current Population Survey and based on family size and composition. The Children with Special Health Care Needs Screener instrument was used to identify adolescents with special health care needs.25 In addition, if an adolescent was ever diagnosed with asthma we defined him/her as having asthma. 110 Statistical Analyses To describe ED utilization by low-income adolescents, we calculated the proportion of adolescents with any ED use and the number of ED visits per year for three access measures (insurance coverage, USC, and ambulatory care use), sociodemographic characteristics (age, race/ethnicity, interview language, region, residence and income) and three health indicators (health status, special health care needs (SHCN) and asthma). To examine whether the relationship between ambulatory care use and ED use was the same regardless of health status, we conducted analyses of variance (ANOVA) stratified by the three health measures. Within each health measure stratum, we tested for differences in the mean annual ambulatory care visits by level of ED use (total annual visits: 0, 1, 2, 3-4). In addition, we used a multivariable logistic regression model to estimate the independent effects of insurance coverage, USC, age, race/ethnicity, interview language, region, residence, income, health status, SHCN and asthma on the likelihood of any ED use. Adjusted odds ratios and corresponding 95 percent confidence intervals (CI) were calculated. All analyses were stratified by gender because adolescent emergency department use can differ substantially for males and females depending on their age.19 In addition, unless otherwise stated, results were statistically weighted to produce nationally representative estimates. To account for the complex survey design of the Medical Expenditure Panel Survey, weighted analyses were conducted using the Taylor series linearization method in Stata 10.0 (Stata Corporation®, College Station, TX). RESULTS Sample and Population Characteristics A total of 2,162 females and 2,207 males aged 10 through 17 years whose family incomes were less than 200 percent of federal poverty level (FPL) and whose households participated in the MEPS in 2003 and 2005 were included in our study (Tables 3.2 and 3.3). They represented a total of 10.6 million low-income adolescents in the United States. Among adolescents with both private and public insurance, nearly 90 percent were covered by both types of insurance for at least one month during the study year. Emergency Department Use Approximately 12 percent of low-income adolescents visited the emergency department (ED) during the study year (Tables 3.2 and 3.3). The annual ED visit rate for females and males was 1,534 per 10,000 adolescents and 1,453 per 10,000 adolescents, respectively. While 10-14 year old females and males had similar annual ED rates (1,413 and 1,502 per 10,000, respectively), the ED rates for females aged 15 to 17 years was substantially higher than their male counterparts (1,837 and 1,333 per 10,000, respectively). The total number of visits for both females and males ranged from zero to four. For females, bivariate analyses indicated that ED use varied substantially by insurance coverage, health status and special health care needs (SHCN) and did not differ by USC or asthma diagnosis. While 21.0 percent of females with both private and public 111 112 insurance and 15.6 percent of females with full-year public insurance had any ED use during the year, only 5.2 percent of females with full-year private insurance coverage had any ED use. On the other hand, full-year uninsured females had ED use rates that were almost as low as those of fully insured young women (6.2%). Females with fair/poor health status were more likely to use the ED than females in excellent/very good /good health (26.4 percent vs. 11.0 percent, respectively) as were females with SHCN as compared to females without SHCN (18.6 percent vs. 9.6 percent, respectively). A similar pattern is observed for females with asthma, (15.9% with vs. 11.3% without asthma). Adolescent females whose household respondent’s interview was conducted at least partly in Spanish, or in a language other than English, had lower rates of ED utilization than females whose household respondent completed the interviews in English (641 and 776 per 10,000 vs. 1,730 per 10,000, respectively). For male adolescents, ED use varied substantially by USC, health status and asthma diagnosis but did not differ by insurance coverage. Additionally, unlike female adolescents, the relationship between USC and ED use was inconsistent for male adolescents. As compared to males who experienced at least 2 barriers to care or who did not have a USC, those who had a USC and who did not experience a barrier to care had lower ED visit rates (0 barriers: 1,418 per 10,000, 1 barrier: 896 per 10,000, 2-5 barriers: 1,682 per 10,000, no USC: 1,633 per 10,000). Similar to females, males with fair/poor health were more likely to have had an ED visit during the year than males with excellent/very good/good health (20.1 vs. 11.6, respectively). In addition, males with asthma were more likely to use the ED during the year than males who did not have asthma (19.9% vs. 10.9%). As was reported for adolescent females, adolescent males 113 whose household respondent’s interview language was conducted at least partly in Spanish or in a language other than English also had lower rates of ED utilization than males whose household respondent completed the interviews in English (621 and 582 per 10,000 vs. 1,643 per 10,000). ED visit rates were strongly associated with ambulatory care use levels during the year (Tables 3.2 and 3.3, Figure 3.2). Both males and females who had at least one ambulatory care visit had higher ED visit rates than adolescents who did not use any ambulatory care during the year (females: 1,932 vs. 903 per 10,000; males: 1,861 vs. 887 per 10,000). Among female adolescents, there was an increase in the number of ambulatory care visits by ED use and was highest among females who had four ED visits (7.6). For males, the relationship between ambulatory care visits and ED visits was less consistent and the number of ambulatory care visits was highest (11.8) for males with three ED visits. After stratifying by three health indicators (health status, special health care needs (SHCN) and asthma), substantial differences in the number of ambulatory care visits by ED use persisted for both female and male adolescents (Table 3.4); however, among both female and male adolescents, the relationship between ambulatory care visits and ED use was inconsistent within each health measure stratum. Among females with fair or poor health, the average annual number of ambulatory care visits ranged from 4.9 for adolescents who made 2 ED visits during the year to 18.7 for adolescents who made 3 to 4 ED visits during the year. Similarly, among males in fair or poor health, the average annual number of ambulatory care visits ranged from 0.6 for adolescents who made 2 ED visits during the year to 7 for adolescents who made 3-4 ED visits during the year. 114 Multivariable Analysis of Any Emergency Department Use We used a logistic regression model to examine the associations between insurance coverage, USC and any ED use while controlling for sociodemographic characteristics and health indicators. The results are presented in Table 3.5. In the multivariable analysis, health care access, as measured by insurance coverage and having a usual source of care, was associated with any ED use for females but not for males. As compared to females with full-year private insurance, controlling for USC, age, race/ethnicity, interview language, region, residence, income, health status, SHCN and asthma, the odds of having any ED use was 3.2 (95% CI: 1.8-5.7) for females with full- year public insurance, 5.9 (95% CI: 2.9-12.0) for females with both private and public insurance, 2.1 (95% CI: 1.1-4.0) for females who were uninsured for part of the year and 1.8 (95% CI: 0.9-3.7) for those uninsured the entire year. There was no consistent relationship between having a USC and/or access barriers to that provider and ED use among adolescent females. For males, after controlling for illness and socio- demographic factors neither insurance nor USC were associated with any ED use (Table 3.5). Health indicators were associated with higher odds of any ED use for both genders. For both females and males, adolescents with special health care needs were more likely to have any ED use during the year than adolescents who did not have special health care needs (females: 1.8 (95% CI: 1.2-2.6); males: 1.4 (1.0-2.0)). For females, the odds of any ED use for adolescents with fair/poor health was 2.2 (95% CI: 1.3-3.9) times that of adolescents with excellent/very good/good health status. For males, the odds of 115 any ED use for adolescents with asthma were 1.6 (95% CI: 1.0-2.5) times that of adolescents who did not have asthma. In addition, for both females and males, adolescents whose interview language was not English had substantially lower odds of any ED use than adolescents whose household respondent completed the MEPS interview entirely in English (females: 0.5 (95% CI: 0.3-0.8); males: 0.3 (95% CI: 0.2- 0.5)). DISCUSSION Using the Medical Expenditure Panel Survey, we examined the relationship between low-income adolescents’ access to and use of ambulatory care services and their likelihood and volume of ED utilization. Overall, the associations between the three broad access measures (insurance coverage, usual source of care (USC) and ambulatory care) and ED use were inconsistent, differed for male and female adolescents and suggested that ED use in this population is complex and driven by multiple, gender- specific factors. We found important gender differences in both the overall ED utilization rates and the associations for insurance coverage, adolescent health and ED use. For adolescents aged 10 to 14 years, ED rates were similar for males and females. However, among 15 to 17 year olds, ED rates were higher for females than males. This is consistent with previous research and may result from gender differences in health care needs and care seeking behaviors.19 Previous research demonstrates that while injuries account for a majority of emergency department visits made by younger adolescent males and females, gender differences in the type of ED visits that are made emerge in middle adolescence and continue through adulthood.3,14,19 While a majority of ED visits for males aged 15 to 17 years are due to injuries, noninjuries account for most of the ED visits made by females in this age group. 19 For female adolescents, ED visits associated with pregnancy and sexual activity increase dramatically during middle adolescence and largely explain their higher rates of ED utilization.15,19 116 117 Gender differences in underlying health care needs and care seeking behaviors may also explain why, after adjusting for socioeconomic characteristics and health status, we found that insurance coverage was only associated with ED use by low-income female adolescents. Our results suggest that, among females, differences in ED use by insurance coverage may be driven by differences in the underlying health conditions inherent in each insurance group rather than differences in insurance coverage. Adolescent females who were both privately and publicly insured during the year had over 5 times the adjusted odds of ED use of their full-year privately insured counterparts. This disproportionately higher ED use may result from the higher illness burden and more substantial health care needs of the both privately and publicly insured population. Approximately 90% of these females were simultaneously publicly and privately insured for at least one month during the year. Simultaneous insurance coverage is often obtained to pay for high health care costs that result from substantial health care utilization. Individuals who are less than 65 years old receive social security benefits because of a disability. If they receive these benefits for at least 24 months, they are automatically enrolled in Medicare (one form of public insurance) and are mailed an insurance card. In December 2000, approximately 279,924 U.S. adolescents aged 13 to 17 years received SSI (http://www.ssa.gov/policy/docs/ssb/v66n2/v66n2p21.html). Many states also have medically eligible programs that provide sick children and adolescents with public insurance to cover their high medical expenses that are not otherwise paid for by their private insurance. In addition, we found that female adolescents with full-year public insurance had 118 3.2 times the odds of ED use as compared those who had full-year private insurance. It is possible that full-year publicly insured females were more likely to be pregnant than adolescents with full-year private insurance and were more likely to have pregnancy- related ED visits. One way that low-income adolescents become eligible for public insurance coverage is by being pregnant.26 This would explain the higher ED utilization by full-year publicly insured as compared to full-year privately insured females, particularly those aged 15 to 17 years.3,19 In contrast, research demonstrates that adolescent males primarily seek health care in the ED for injuries (e.g. sports-related and motor-vehicle/traffic-related). The incidence of injuries in this low-income population is likely to be unrelated to insurance coverage and would explain why ED use did not differ by insurance coverage. Initially, we hypothesized that adolescents in low-income families who had a primary care provider with no barriers to care would have the lowest emergency department consumption. National and international studies indicate that having a primary care provider/usual source of care (USC) positively impacts the health of children and adults and reduces socioeconomic disparities in health.27 By providing first contact, coordinated, comprehensive care over a period of time, a medical home can improve health, reduce preventable illness episodes and lower health care costs.13,28,29 Given low-income adolescents’ historically high rates of nonurgent ED use, dependence on the ED for routine care and preventable health conditions, researchers and policy makers have postulated that access to routine, preventive, primary care would reduce ED use in this population.3,7,13,30,31 However, our study found that even after accounting for barriers to care and health conditions, having a usual source of care (USC) was not 119 associated with lower ED utilization among U.S. female and male adolescents in low- income families. For adolescents who were reported to have a primary care provider, nearly all had a USC who provided first contact, coordinated, longitudinal care. Our results suggest that having a medical home may not be enough to alter ED use patterns in this population. It is likely that it is not only the presence of the USC, but the strength of the patient-provider relationship, the quality of care that they provide, as well as family preferences, and adolescents’ health care needs, and health seeking behaviors that impact their health services use patterns.30,32 Ryan and colleagues (2001) compared the presence of a USC to not having a USC on emergency services receipt among rural adolescents residing in a single state and found no association.33 However, they did find that adolescents whose regular source of care provided both preventive and illness care were less likely to receive care in the emergency department than adolescents who had different providers for preventive and illness care. In addition, Brousseau and colleagues reported substantially lower nonurgent and urgent ED use among Medicaid enrolled children and adolescents in Wisconsin whose parents reported receiving high-quality primary care as compared to those who did not report receiving such care. Also, a recent report on adolescent health services by the National Research Council and the Institute of Medicine may explain why we did not find an association between a USC and ED use among low-income adolescents. They reported that providers who deliver care to adolescents are not trained to address their unique health care needs and that emergency departments and other safety-net sites may provide more accessible, and effective health care to some adolescents.30 120 Higher ambulatory care use by male and female adolescents in low-income families was not associated with lower ED utilization. In general, we found that both male and female adolescents who had higher ambulatory care utilization also made more ED visits during the year. Adolescents and children in families with low-incomes are more likely to have chronic health conditions, be in fair or poor health, report activity limitations, experience emotional and behavioral problems, have special health care needs and consume a greater amount of health services as compared to those whose families have higher incomes. 33-35 In our study, multivariable results indicated that worse health, as measured by health status, SHCN and asthma, was associated with increased odds of ED utilization. To further explore illness as a possible explanation for having both high ambulatory care and ED use, we examined the association between ambulatory care use and ED visits stratified by each of the three health measures (health status, SHCN and asthma) and found a complex pattern of utilization. Our results suggest that poor health status is not the only driver of high ambulatory care and ED use among adolescent females and males in low-income families. Previous adolescent- specific research indicates that both the USC and medical need/health status are differentially associated with outpatient care use. 33 The differential effects of multiple exposures may help to explain the stratified results. Whereas greater medical need is associated with increased use of outpatient health services, having a USC has been shown to reduce both health care need and health care use13,28,29,34,35 Furthermore, unmeasured family and individual preferences may also contribute to ambulatory care and ED use patterns.30,33,36 Our findings have important policy implications and suggest that providing 121 financial access through health insurance and having a medical home may not be enough to decrease emergency department use in female and male adolescents in low-income families.7,30,33,36 A more comprehensive, gender-specific approach that addresses their specific health needs, access, and family and individual health care preferences and behaviors may be needed to reduce ED use and to provide adolescents with an effective, efficient, prevention-based health care model that addresses their complex, long-term health care needs. Our study has several limitations. First, a household respondent, often a parent, provided all adolescent information. This may result in the misclassification of an adolescent’s relationship with his/her USC and his/her health services use. The respondent may underestimate the barriers to quality, confidential care that an adolescent encounters and the volume of care that he/she receives. Often, respondents/parents are not aware of the spectrum of care that adolescents seek.31 Adolescents may receive confidential care at a school-based health center school or within the community without their parents’ knowledge. 37 Second, due to the nature of the MEPS data, we were unable to explore the temporal sequence of adolescents’ emergency department and ambulatory care utilization. Third, we restricted our study population to adolescents in low-income families and, therefore, limit the generalizability of our findings. Finally, although we used three health measures (health status, SHCN and asthma), it is possible that these measures did not capture the burden of illness in this population and there may be residual confounding by severity of health conditions or health care needs and by patient health care preferences. CONCLUSIONS Approximately 40 percent of adolescents are members of low-income families and this proportion is growing.7 Our study demonstrates that emergency department utilization by low-income adolescents is complex and differs substantially by gender and suggests that improving the current model of adolescent health care will require addressing gender-specific health care needs and care seeking behaviors. With the recent SCHIP reauthorization and a renewed, national commitment to improving the delivery of health care to adolescents, we have a tremendous opportunity to restructure the way that care is delivered to vulnerable adolescents and to ensure that cost-effective quality care is provided even during an economic downturn. Future research is needed to understand how to best improve the quality care that is delivered to adolescents and to explore gender differences in care seeking behaviors. 122 REFERENCES 1. National Center for Health Statistics. Health, United States, 2008 With Chartbook. ed. Hyattsville, MD: 2009. 2. Nawar EW, Niska RW, Xu J. National Hospital Ambulatory Medical Care Survey: 2005 emergency department summary. Adv Data. 2007;1-32. 3. Ziv A, Boulet JR, Slap GB. Emergency department utilization by adolescents in the United States. Pediatrics. 1998;101:987-994. 4. Brindis CD, Morreale MC, English A. The unique health care needs of adolescents. Future Child. 2003;13:117-135. 5. Klein JD, Slap GB, Elster AB, Schonberg SK. Access to health care for adolescents. A position paper of the Society for Adolescent Medicine. J Adolesc Health. 1992;13:162-170. 6. Luo X, Liu G, Frush K, Hey LA. Children's health insurance status and emergency department utilization in the United States. Pediatrics. 2003;112:314-319. 7. Newacheck PW, Hung YY, Park MJ, Brindis CD, Irwin CEJ. Disparities in adolescent health and health care: does socioeconomic status matter? Health Serv Res. 2003;38:1235-1252. 8. Halfon N, Newacheck PW, Wood DL, St Peter RF. Routine emergency department use for sick care by children in the United States. Pediatrics. 1996;98:28-34. 123 124 9. Owens PL, Zodet MW, Berdahl T, Dougherty D, McCormick MC, Simpson LA. Annual report on health care for children and youth in the United States: focus on injury-related emergency department utilization and expenditures. Ambul Pediatr. 2008;8:219-240.e17. 10. Newacheck PW, Park MJ, Brindis CD, Biehl M, Irwin CEJ. Trends in private and public health insurance for adolescents. JAMA. 2004;291:1231-1237. 11. Brousseau DC, Hoffmann RG, Nattinger AB, Flores G, Zhang Y, Gorelick M. Quality of primary care and subsequent pediatric emergency department utilization. Pediatrics. 2007;119:1131-1138. 12. Slifkin RT, Freeman VA, Silberman P. Effect of the North Carolina State Children's Health Insurance Program on Beneficiary Access to Care. Arch Pediatr Adolesc Med. 2002;156:1223-1229. 13. Achieving quality health services for adolescents. Pediatrics. 2008;121:1263-1270. 14. Bertakis KD, Azari R, Helms LJ, Callahan EJ, Robbins JA. Gender differences in the utilization of health care services. J Fam Pract. 2000;49:147-152. 15. Marcell AV, Klein JD, Fischer I, Allan MJ, Kokotailo PK. Male adolescent use of health care services: where are the boys? J Adolesc Health. 2002;30:35-43. 16. Committee on Adolescent Health Care Services and Models of Care for Treatment, Prevention and Healthy Development, National Research Council, Institute of Medicine (Contributor). Challenges in Adolescent Heath Care : Workshop Report. 2007 17. Agency for Healthcare Research and Quality. Medical Expenditure Panel Survey: Survey Questionnaires--Household Component _. 125 18. The World Health Organization. Child and Adolescent Health and Development: Overview of CAH. 2004 19. McKay AP, Fingerhut LA, Duran CR. Adolescent Health Chartbook. Health, United States, 2000. eds. Hyattsville, Maryland: National Center for Health Statistics.; 2000. 20. Ensign J, Santelli J. Health status and service use. Comparison of adolescents at a school-based health clinic with homeless adolescents. Arch Pediatr Adolesc Med. 1998;152:20-24. 21. Dombkowski KJ, Stanley R, Clark SJ. Influence of Medicaid managed care enrollment on emergency department utilization by children. Arch Pediatr Adolesc Med. 2004;158:17-21. 22. McCaig LF, Burt CW. National Hospital Ambulatory Medical Care Survey: 1999 emergency department summary. Adv Data. 2001;1-34. 23. Mistry RD, Hoffmann RG, Yauck JS, Brousseau DC. Association between parental and childhood emergency department utilization. Pediatrics. 2005;115:e147-51. 24. Elster AB, Kuznets NJ. AMA Guidelines for Adolescent Preventive Services (GAPS). 1994 25. Bethell CD, Read D, Stein RE, Blumberg SJ, Wells N, Newacheck PW. Identifying children with special health care needs: development and evaluation of a short screening instrument. Ambul Pediatr. 2002;2:38-48. 26. Schneider A, Elias R, Rousseau D, Wachino V. The Medicaid Resource Book. 2002;215. 126 27. Starfield B. Insurance and the U.S. health care system. N Engl J Med. 2005;353:418-419. 28. Sia C, Tonniges TF, Osterhus E, Taba S. History of the medical home concept. Pediatrics. 2004;113:1473-1478. 29. Starfield B. Primary Care: Concept, Evaluation, and Policy. 1992 30. Committee on Adolescent Health Care Services and Models of Care for Treatment, Prevention and Healthy Development. Adolescent Health Services: Missing Opportunities. 2009. 31. Ozer EM, Park MJ, Paul T, Brindis CD, Irwin CEJ. America's Adolescents: Are They Healthy? eds. San Francisco: University of California, San Francisco, National Adolescent Health Information Center; 2003. 32. Brousseau DC, Gorelick MH, Hoffmann RG, Flores G, Nattinger AB. Primary care quality and subsequent emergency department utilization for children in Wisconsin Medicaid. Acad Pediatr. 2009;9:33-39. 33. Ryan S, Riley A, Kang M, Starfield B. The effects of regular source of care and health need on medical care use among rural adolescents. Arch Pediatr Adolesc Med. 2001;155:184-190. 34. Homer CJ, Klatka K, Romm D, Kuhlthau K, Bloom S, Newacheck P, Van Cleave J, Perrin JM. A review of the evidence for the medical home for children with special health care needs. Pediatrics. 2008;122:e922-37. 35. Newacheck PW, Kim SE. A national profile of health care utilization and expenditures for children with special health care needs. Arch Pediatr Adolesc Med. 2005;159:10-17. 127 36. Ford CA, Bearman PS, Moody J. Foregone health care among adolescents. JAMA. 1999;282:2227-2234. 37. Leatherman S, McCarthy D. Quality of Care for Children and Adolescents: A Chartbook. eds. The Commonwealth Fund; 2004. 128 Table 3.1. Five questions used to identify USC barriers to health care encountered by low-income adolescents, Medical Panel Expenditure Survey, United States, 2003 and 2005 MEPS Access to USC Provider Question Possible Responses 1. How long does it take (adolescent) to (a) Less than 15 minutes travel to (USC provider)? (b) 15 to 30 minutes (c) 31 to 60 minutes* (d) 61 to 90 minutes* (e) 91 to 120 minutes* (f) >120 minutes* (g) Don't Know (h) Refused 2. How difficult is it for (adolescent) to get (a) Very difficult* to (USC provider)? (b) Somewhat difficult* (c) Not too difficult (d) Not at all difficult (e) Don't Know (f) Refused 3. How difficult is it to contact {a medical (a) Very difficult* person at} (USC provider) during regular (b) Somewhat difficult* business hours over the telephone about a (c) Not too difficult health problem? (d) Not at all difficult 4. Does (USC provider) have office hours at (a) Yes night or on weekends? (b) No* (c) Don't Know (d) Refused 5. How difficult is it to contact {a medical (a) Very difficult* person at} (USC provider) after their (b) Somewhat difficult* regular hours in case of urgent medical (c) Not too difficult needs? (d) Not at all difficult (e) Don't Know (f) Refused *Response indicates barrier to health care encountered. Abbreviation: USC, usual source of care 129 Table 3.2 Health indicator variables and emergency department use for low-income, female adolescents, United States, 2003 and 2005 Sociodemographic Unweighted Population Any ED Visits Annual ED Characteristics and Distribution Distribution During Year, Visit Rate Ambulatory Care % per 10,000 (SE) Yes No (n=256) (n=1,906) Total 2,162 5,043,400 11.8 88.3 1,534 (145) Insurance Full-year private 308 1,018,386 5.2 94.8 679 (181) Full-year public 1,078 2,312,389 15.6 84.4 2,075 (244) Private and public* 110 287,653 21.0 79.0 2,736 (693) Part-year uninsured 391 924,593 9.6 90.4 1,174 (200) Full-year uninsured 275 500,379 6.2 93.8 750 (212) Usual Source of Care (not ED) Yes, 0 barriers 390 982,993 13.4 86.6 1,621 (321) Yes, 1 barrier 474 1,156,645 10.6 89.4 1,286 (220) Yes, 2-5 barriers 871 2,032,963 12.5 87.5 1,790 (231) No 417 845,488 10.0 90.0 1,203 (254) Missing 10 25,312 Ambulatory Care Yes 1,229 3,093,644 14.7 85.3 1,932 (191) No 933 1,949,756 7.1 92.9 903 (175) 130 Table 3.2. (continued) Age 10-14 years 1,564 3,601,446 11.1 88.9 1,413 (162) 15-17 years 598 1,441,954 13.5 86.5 1,837 (272) Race/ethnicity Non-Hispanic white 482 1,863,024 13.4 86.7 1,743 (254) Non-Hispanic black 558 1,272,577 13.7 86.3 1,740 (270) Hispanic 1,010 1,548,997 8.3 91.8 1,114 (153) Other 112 358,802 11.7 88.3 1,531 (540) Interview Language English 1,463 4,034,829 13.3 86.7 1,730 (173) English and Spanish 108 186,417 6.4 93.6 641 (290) Non-English 591 822,154 5.5 94.5 776 (155) Region Northeast 262 722,519 10.4 89.6 1,275 (347) Midwest 327 996,482 15.9 84.1 2,098 (370) South 840 1,882,358 12.9 87.1 1,732 (280) West 733 1,442,042 8.0 92.0 1,017 (165) Residence Rural 429 1,068,899 12.9 87.1 1,661 (250) Urban 1,733 3,974,501 11.4 88.6 1,500 (171) Income (% FPL) 100% - <200% 1,130 2,862,038 9.4 90.6 1,198 (148) 0% - <100% 1,032 2,181,362 14.8 85.2 1,976 (242) 131 Table 3.2. (continued) Health Status Excellent/very good/good 2,044 4,785,867 11.0 89.0 1,396 (133) Fair/poor 117 257,533 26.4 73.6 4,107 (836) Missing 1 0 SHCN No 1,705 3,864,373 9.6 90.4 1,259 (152) Yes 444 1,143,186 18.6 81.4 2,387 (314) Missing 13 35,841 Asthma No 1,947 4,506,882 11.3 88.7 1,419 (146) Yes 211 529,720 15.9 84.1 2,537 (468) Missing 4 6,798 *256,4674 (89.2%) of public and privately insured were covered by both types of insurance for at least one month during the year. Abbreviation: ED, emergency department; FPL, federal poverty level; SHCN, special health care needs. Note: Weighted totals for adolescent subgroups may not all equal population total due to rounding. 132 Table 3.3 Health indicator variables and emergency department use for low-income male adolescents, United States, 2003 and 2005 Sociodemographic Unweighted Population Any ED Visits Annual ED Characteristics Distribution Distribution During Year, Visit Rate and Ambulatory % per 10,000 Care Yes No (SE) (n=254) (n=1,953) Total 2,207 5,527,632 12.0 88.0 1,453 (121) Insurance Full-year private 321 2,429,500 11.0 89.0 1,263 (249) Full-year public 1,097 1,113,569 13.1 86.9 1,642 (168) Private and public* 120 314,712 10.4 89.6 1,411 (615) Part-year uninsured 386 1,061,801 12.6 87.5 1,352 (239) Full-year uninsured 283 608,051 9.3 90.7 1,245 (375) Usual Source of Care (not ED) Yes, 0 barriers 383 1,143,825 12.5 87.6 1,418 (242) Yes, 1 barrier 471 1,221,349 7.5 92.5 896 (215) Yes, 2-5 barriers 851 2,062,682 13.3 86.7 1,682 (220) No 488 1,074,215 13.7 86.3 1,633 (248) Missing 14 25,561 Ambulatory Care Yes 1,183 3,215,527 15.2 84.8 1,861 (183) No 1,024 2,312,105 7.6 92.4 887 (121) 133 Table 3.3. (continued) Sociodemographic Unweighted Population Any ED Visits During Annual ED Characteristics Distribution Distribution Year, Visit Rate per and Ambulatory % 10,000 Care Yes No (SE) (n=254) (n=1,953) Age 10-14 years 1,614 3,928,792 12.2 87.8 1,502 (155) 15-17 years 593 1,598,840 11.5 88.5 1,333 (193) Race/ethnicity Non-Hispanic white 543 2,169,151 13.8 86.2 1,725 (247) Non-Hispanic black 559 1,386,020 12.6 87.4 1,475 (190) Hispanic 972 1,563,546 9.6 90.4 1,071 (138) Other 133 408,916 9.8 90.2 1,402 (436) Interview Language English 1,541 4,535,692 13.5 86.5 1,643 (147) English and Spanish 76 136,358 6.2 93.8 621 (322) Non-English 590 855,582 5.1 94.9 582 (100) Region Northeast 268 934,259 13.1 86.9 1,703 (420) Midwest 318 979,350 13.2 86.9 1,577 (233) South 884 2,154,827 13.8 86.2 1,617 (201) West 737 1,459,197 7.9 92.1 969 (158) Residence Rural 427 1,026,400 15.7 84.3 1,999 (355) Urban 1,780 4,501,232 11.2 88.8 1,329 (122) Income (% FPL) 100% - <200% 1,143 3,085,985 11.2 88.8 1,276 (141) 0% - <100% 1,064 2,441,647 13.1 86.9 1,677 (177) 134 Table 3.3. (continued) Sociodemographic Unweighted Population Any ED Visits During Annual ED Characteristics Distribution Distribution Year, Visit Rate and Ambulatory % per 10,000 Care Yes No (SE) (n=254) (n=1,953) Health Status Excellent/very good/good 2,080 5,253,100 11.6 88.4 1,412 (128) Fair/poor 123 274,532 20.1 79.9 2,238 (513) Missing 4 0 SHCN No 1,678 4,002,066 10.3 89.7 1,165 (112) Yes 519 1,507,594 16.7 83.3 2,228 (334) Missing 10 17,972 Asthma No 1,946 4,810,206 10.9 89.2 1,294 (116) Yes 257 713,753 19.9 80.1 2,533 (533) Missing 4 3,674 *279,165 (88.7%) of public and privately insured adolescents were covered by both types of insurance for at least one month during the year. Abbreviation: ED, emergency department; FPL, federal poverty level; SHCN, special health care needs. Note: Weighted totals for adolescent subgroups may not all equal population total due to rounding. 135 Table 3.4. The association between ambulatory care use and emergency department visits during the year stratified by three health measures for low-income adolescents, United States, 2003 and 2005 Mean Ambulatory Care Visits (sd) Health Measures p-value* 0 ED 2 ED 3-4 ED Visits 1 ED Visit Visits Visits FEMALES (n= 4,450,880) (n=455,583) (n=103,123) (n=33,814) Health Status Excellent/very 2.1 good/good (6.4)** 3.7 (8.2) 3.7 (5.1) 1.4 (2.8) 0.001 5.2 13.4 Fair/poor (13.7) (16.7) 4.9 (5.9) 18.7 (7.7) 0.001 SHCN No 1.3 (3.7) 2.7 (4.5) 3.4 (4.4) 2.1 (6.2) <0.001 11.5 Yes 5.6 (11.4) 7.9 (14.8) 5.8 (7.6) (13.7) 0.40 Asthma No 2.0 (6.3) 3.8 (7.0) 3.5 (4.7) 4.0 (12.2) 0.002 11.2 10.1 Yes 4.6 (9.8) (23.1) 5.6 (6.8) (8.2) 0.16 (n= (n= MALES 4,863,250) 564,144) (n= 67,109) (n=33,131) Health Status Excellent/very 11.2 good/good 4.6 (9.8) (23.1) 5.6 (6.8) 10.1 (8.2) 0.04 Fair/poor 5.0 (8.7) 5.3 (8.4) 0.6 (1.5) 7 (0) <0.001 SHCN No 1.0 (2.8) 2.6 (6.0) 1.6 (2.1) 1.4 (0.7) 0.03 12.8 Yes 4.8 (9.8) 7.3 (18.4) 3.3 (5.9) (15.3) 0.15 Asthma No 1.8 (6.1) 4.3 (13.9) 2.1 (3.4) 5.8 (13.9) 0.15 16.3 Yes 3.2 (6.8) 4.1 (6.7) 3.5 (6.4) (12.1) 0.09 *ANOVA p-value calculated using linear regression. ** Mean ambulatory care visits among female adolescents who had no ED visits during the year and who were reported to be in excellent, very good, or good health. Sd=standard deviation. 136 Table 3.5. Access variables, sociodemographic characteristics, health status and emergency department use by gender for low-income adolescents, United States, 2003 and 2005 Access Variables and Adjusted* OR Sociodemographic (95% CI) Characteristics Females Males Insurance Full-year private 1 1 Full-year public 3.2 (1.8-5.7) 1.3 (0.8-2.0) Private and public 5.9 (2.9-12.0) 0.9 (0.4-1.9) Part-year uninsured 2.1 (1.1-4.0) 1.2 (0.7-2.0) Full-year uninsured 1.8 (0.9-3.7) 0.9 (0.5-1.8) Usual Source of Care (not ED) Yes, 0 barriers 1 1 Yes, 1 barrier 0.7 (0.4-1.2) 0.6 (0.3-1.2) Yes, 2-5 barriers 0.8 (0.5-1.2) 1.1 (0.7-1.7) No 0.7 (0.4-1.2) 1.5 (0.9-2.6) Age 10-14 years 1 1 15-17 years 1.3 (0.9-1.8) 0.9 (0.6-1.3) Race/ethnicity Non-Hispanic white 1 1 Non-Hispanic black 0.9 (0.6-1.4) 0.8 (0.6-1.3) Hispanic 1.0 (0.6-1.6) 1.3 (0.8-2.2) Other 0.9 (0.4-2.3) 0.9 (0.5-1.8) Interview Language English 1 1 English and Spanish 0.5 (0.2-1.4) 0.4 (0.1-1.3) Non-English 0.5 (0.3-0.8) 0.3 (0.2-0.5) 137 Table 3.5. (continued) Region Northeast 1 1 Midwest 1.8 (0.9-3.5) 1.0 (0.6-1.7) South 1.4 (0.7-2.8) 1.1 (0.7-1.8) West 1.0 (0.5-1.9) 0.7 (0.4-1.1) Residence Rural 1 1 Urban 1.1 (0.7-1.7) 0.8 (0.5-1.1) Income (% FPL) 100% - <200% 1 1 0% - <100% 1.3 (0.9- 1.8) 1.1 (0.8-1.6) Health Status Excellent/very good/good 1 1 Fair/poor 2.2 (1.3-3.9) 1.3 (0.7-2.4) SHCN No 1 1 Yes 1.8 (1.2-2.6) 1.4 (1.0-2.0) Asthma No 1 1 Yes 1.0 (0.6-1.5) 1.6 (1.0-2.5) *Adjusted for all variables in table. Abbreviation: ED, emergency department; OR, odds ratio; CI, confidence interval; SHCN, special health care needs. 138 Figure 3.1. The Medical Expenditure Panel Survey Design, 2003-2005 2003 (Study Year) 2004 2005 (Study Year) January December January December January December Panel 7 Round 3 Round 4 Round 5 2002-2003 Panel 8 Round 1 Round 2 Round 3 Round 4 Round 5 2003-2004 Panel 9 Round 1 Round 2 Round 3 Round 4 Round 5 2004-2005 Panel 10 Round 1 Round 2 Round 3 2005-2006 Note: Survey sample drawn from MEPS panels 7 through 10. Study information obtained from highlighted rounds. Source: Agency for Healthcare Research and Quality. Medical Expenditure Panel Survey: Survey Questionnaires--Household Component. Available at: http://www.meps.ahrq.gov/mepsweb/survey_comp/survey.jsp. 139 Figure 3.2 Mean ambulatory care visits by emergency department visits, low-income female and male adolescents, United States, 2003 and 2005 25.00 Mean Ambulatory Care Visits and Upper 95% Confidence Limit 20.00 15.00 11.8 Fem ales Males 10.00 7.6 4.7 3.9 5.4 4.2 5.00 2.3 3.3 2.2 2.0 0.00 0 1 2 3 4 Number of Emergency Department Visits