What is the prevalence of children with special health care needs? toward an understanding of variations in findings and methods across three national surveys

Objectives To compare and consider sources of variation in the prevalence and characteristics of children with special health care needs (CSHCN) identified using the CSHCN Screener across the 2001 National Survey of Children with Special Health Care Needs (NS-CSHCN), the 2003 National Survey of Children's Health (NSCH) and the 2001 - 2004 Medical Expenditures Panel Surveys (MEPS). Methods For each survey, national prevalence rates and the demographic, health and health need characteristics of CSHCN age 0 - 17 years were estimated and compared. The stability of CSHCN state prevalence rankings between the NS-CSHCN and NSCH was assessed. Logistic regression analysis produced adjusted odds of identification for subgroups of children. CSHCN Screener sampling and administration were profiled across eight methodology parameters for each survey. Results Compared to the NS-CSHCN (12.8%), CSHCN prevalence for children age 0 - 17 years was 4.8 points higher for the NSCH (17.6%) and 6.0 - 6.5 points higher across the four 2001 - 2004 MEPS datasets (18.8 - 19.3%). The adjusted probability of identification by child's demographic characteristics was stable across all datasets as were state prevalence rankings between the NS-CSHCN and the NSCH. CSHCN identified through the NS-CSHCN were slightly more likely to meet more than one CSHCN Screener criteria, to meet the '' above routine need or use of services '' criterion and to miss two or more weeks of school due to illness compared to the NSCH, suggesting that CSHCN with less complex and/or serious health consequences may not have been as likely to be identified through the NS-CSHCN. CSHCN prevalence did not change significantly between 2001 and 2004 MEPS, although some off-setting increases or decreases in the proportion of CSHCN meeting specific CSHCN Screener criteria occurred and reflects trends toward increased prescription medication use in children. Conclusions When CSHCN Screener administration methods remained similar across years (2001 - 2004 MEPS), CSHCN prevalence rates were stable. When methods varied between surveys, CSHCN prevalence rates differed. These differences suggest that prevalence is best expressed as a range, rather than as a point estimate. However, once identified, characteristics and health needs of CSHCN were stable across surveys evaluated, each of which has unique strengths for purposes of policy and research.