Uninsured Children: How We Count Matters

Background. Because children uninsured for less than a full year are often reported as insured, they receive less attention in health policy debates than do the full-year uninsured and are underrecognized as potential users of public insurance programs. Objective. The purpose of this study is to assess the impact on estimates of how many US children are uninsured when alternatives to the full-year uninsured definition are used. Methods. Monthly health insurance coverage data collected from children through age 18 in the 1999 Medical Expenditure Panel Survey were analyzed to estimate prevalence of health insurance gaps among children in terms of the size of part-year and full-year uninsured child population, duration of uninsured gaps, and aggregate uninsured spells. Results. Although 6.6 million ([M] 8.4%) children in the United States were uninsured throughout 1999, an additional 11.4M (14.4%) were uninsured for part of the year. Part-year uninsured gaps accounted for 41.7% of a total of 130M months of missing coverage experienced by all children. Conclusions. Different definitions and measures of who are uninsured can project radically different pictures of the magnitude of the problem. As this study shows, including the part-year uninsured more than doubled the estimated uninsured child population for 1999, and increased the estimated aggregate uninsured months by 71%. As potential users of public coverage, children who have no insurance for part of the year should be included when evaluating challenges to and accomplishments by the State Children’s Health Insurance Program and other public programs. Their significant numbers and the potential burden they place on the health care delivery system argue for them to be counted and for the causes and consequences of short-term uninsured spells to be better understood. Pediatrics 2003;112:e168–e173. URL: http://www.pediatrics.org/cgi/content/full/112/2/ e168; health insurance coverage gaps, part-year uninsured children, short-term uninsured spells, State Children’s Health Insurance Program evaluation. ABBREVIATIONS. SCHIP, State Children’s Health Insurance Program; CPS, Current Population Survey; MEPS, Medical Expenditure Panel Survey; SIPP, Survey of Income and Program Participation; NCHS, National Center for Health Statistics; HC-031, 999 Full Year Population Characteristics File; M, million. How many children are uninsured in the United States? This is a deceptively simple question. There are several alternate ways to define and measure who are uninsured. How one measures may substantially affect the estimated size of the uninsured.1 These estimates, in turn, play a critical role in designing, funding, and evaluating public programs to insure low-income children. One such example is the federal and state partnership to insure low-income children through Title XXI/State Children’s Health Insurance Program (SCHIP). In this program, initial federal funds were allocated to the states according to the number of uninsured lowincome children reported by the Census Bureau based on the Current Population Survey (CPS).2 Since then, considerable resources and attention have been given to the CPS for this purpose. Recognizing the need for state-level data for SCHIP program evaluation as required by Title XXI legislation, Congress appropriated $10M annually beginning in Fiscal Year 2000 to increase the sample size of the CPS so that reliable estimates of low-income uninsured children can be obtained for each state.3 The significance of estimates of uninsured children as a measure of Title XXI success was reiterated in a report to Congressional Committees submitted by the General Accounting Office, advising states to use the CPS and other national surveys to evaluate how much SCHIP has reduced the number of low-income uninsured children.4 To report on the progress of SCHIP in a news conference in August 2002, the Robert Wood Johnson Foundation released a CPSbased report of state-level estimates of overall uninsured children, and those who are eligible for SCHIP or Medicaid but remained uninsured.5,6 How the Uninsured Are Counted A careful reading of widely publicized reports of uninsured children, however, would reveal that a number of children lacking health insurance for less than a full year are often not counted among the uninsured.7,8 This happens because most reports of the uninsured child population are based on the CPS, which is designed to identify only individuals who lacked health insurance throughout the year. In the CPS, respondents are prompted for any coverage of any duration during the survey year, and a single episode of coverage, regardless of its duration, would categorize that individual as being insured.9 Examples of CPS questions on health insurance coverage are given in Appendix A. Because the CPS allows only those lacking health insurance throughout the year to be identified as uninsured (the fullFrom the *Department of Practice and Research, American Academy of Pediatrics, Elk Grove Village, Illinois. Received for publication Oct 11, 2002; accepted Mar 14, 2003. The views expressed are those of the authors and not necessarily those of the American Academy of Pediatrics. Reprint requests to (S-f.S.T.) Department of Practice and Research, American Academy of Pediatrics, 141 Northwest Point Blvd, Elk Grove Village, IL 60007. E-mail: [email protected] PEDIATRICS (ISSN 0031 4005). Copyright © 2003 by the American Academy of Pediatrics. e168 PEDIATRICS Vol. 112 No. 2 August 2003 http://www.pediatrics.org/cgi/content/full/112/2/e168 by guest on April 19, 2017 Downloaded from year uninsured), it counts as insured those who actually had uninsured spells during the 12-month survey period (the part-year uninsured). Nonetheless, the CPS is the most widely used data source because it provides a sample size which permits state-specific estimates (with combined years of data until the sample size was increased in 2002) and a timeliness in reporting annual data that is not matched by other national surveys. Because of its popularity, the CPS is regarded as the benchmark of health insurance coverage, against which other surveys compare their estimates.3 In the past, because of underreported Medicaid coverage and other methodological issues, unadjusted CPS estimates were believed to have been exaggerated and resemble a point-in-time estimate of the uninsured (ie, number uninsured on an average day), rather than the full-year uninsured estimate that the survey was designed to measure.8 Paradoxically, this imprecision also increased the policy value of the CPS because estimates of persons uninsured throughout an entire year would have been too restrictive to use as a principal measure of uninsurance.10 The deployment of various methods to impute and simulate Medicaid and other sources of coverage11,12 and a direct insurance coverage verification question added to the survey since 2001,13 however, successfully “recovered” a substantial number of cases determined to be unreported coverage and, consequently, reduced the uninsured estimate substantially, by 8% to over 25% (Appendix B). Consistent with the intent of the survey, these diligent efforts improved the precision with which the CPS measures the full-year uninsured.14 But in doing so, they also diminished the survey’s utility as a point-in-time representation of the uninsured population. As a result, most experts regard CPS-based estimates as in between a full year and a point-intime measure of the uninsured. Nonetheless, in the absence of an alternative data source that would provide timely, state-level estimates to inform policy debates, the CPS continues to be the benchmark against which other surveys compare their estimates and remains the most popular source of data on children’s health insurance coverage. Less restrictive measures of the uninsured that include individuals without insurance for less than a full year can be estimated from other data sources, but they are not as widely known or accepted as the CPS in the public health policy forum. Several federally funded national surveys, including the Survey of Income and Program Participation (SIPP), the National Health Interview Survey, and the Medical Expenditure Panel Survey (MEPS), do collect data in ways that allow for estimating, at the national level only, the part-year uninsured (for less than a year) and those uninsured at a point in time, in addition to the full-year uninsured. Studies based on 1992 and 1993 SIPP data, for instance, estimated the full-year uninsured US population at above 7%, and the total full-year and part-year uninsured between 20% and 21%, respectively.8 Why It Matters How We Count Defining who are uninsured is more than a semantic or methodological issue. Depending on the size of the uninsured population excluded by the definition, the resulting bias could significantly distort the design of public health insurance programs, shortchange program funding, and influence their chances of success. Policy based only on measures of who are uninsured all year will obscure the existence of many children without insurance and underestimate the need for coverage and potential demand for the program. In turn, the impact of public programs, such as SCHIP and Medicaid, cannot be fully assessed without measuring how they affect part-year uninsured children who qualify for these programs. For instance, does SCHIP reduce the frequency or the length of uninsured spells? Because parents of SCHIP-income eligible children are less likely to have stable jobs that provide affordable family health insurance benefits,15 their children may experience interspersed uninsured spells more frequently than children in other income ranges. Arguably, counting the part-year uninsured is especially critical for SCHIP planning and evaluation. Although most SCHIP programs implement crowd-out provisions in the form of waiting periods subsequent to termination of employer-based coverage and before a child qualifies, only a handful of states require that period to exceed 6 months.16 This implies that a number of children uninsured for less than a full year are in fact eligible to enroll in SCHIP. The purpose of this study is to assess the impact on estimates of how many US children are uninsured when alternatives to the full-year uninsured definition are used: when part-year coverage gaps are included, what is the effect on the total estimated number of US children without health insurance, as compared with a point-in-time estimate? How long are typical part-year coverage gaps? How might they impact demand for public programs?