Multivariate analysis of state variation in underinsurance among children with special health care needs in the US, 2005-06

National attention has focused on providing health insurance coverage for children. Considerably less attention has been given to underinsurance, particularly for children with special health care needs (CSHCN). While about 14% of US children have a special health care need, CSHCN account for 42% of medical costs for children. However, no study has examined state variations in underinsurance. We used the 2005-2006 National Survey of CSHCN, a nationally representative study of 40,000 CSHCN that can provide state estimates, to address state variations in underinsurance. CSHCN with health insurance were considered underinsured if a parent reported that the benefits did not usually or always meet the child's needs; or costs not covered by insurance were not usually or always reasonable; or the insurance plan did not usually or always allow the child to see needed providers. We calculated the unadjusted prevalence for underinsurance for each state. Using logistic regression, we estimated state-specific odds and prevalence for underinsurance after adjusting for poverty level, race/ethnicity, gender, family structure, language use, insurance type, and severity of child's health condition. Unadjusted underinsurance rates for states ranged from 27-47%, which, after multivariate adjustments, diminished to 24-40%. Multivariate analysis indicated that CSHCN's state of residence had a strong association with insurance adequacy. The odds of being underinsured were about 2 times greater for CSHCN in some states compared to Hawaii, which had the lowest underinsurance rate. These factors only partly explain state variations in underinsurance, indicating that the disparity may also be driven by macro-level factors.