Association between Medicaid reimbursement and child influenza vaccination rates.

Abstract

We examined associations between influenza vaccination rates and Medicaid reimbursement rates for vaccine administration among poor children who were eligible for Medicaid (<100% of the federal poverty level in all states). We analyzed 3 consecutive National Immunization Surveys (NISs) to assess influenza vaccination rates among nationally representative children 6 to 23 months of age during the 2005-2006 (unweighted N = 12 885), 2006-2007 (unweighted N = 9238), and 2007-2008 (unweighted N = 11 785) influenza seasons (weighted N = 3.3-4.0 million per season). We categorized children into 3 income levels (poor, near-poor, or nonpoor). We performed analyses with full influenza vaccination as the dependent variable and state Medicaid reimbursement rates (continuous covariate ranging from $2 to $17.86 per vaccination) and terms with income levels as key covariates. In total, 21.0%, 21.3%, and 28.9% of all US children and 11.7%, 11.6%, and 18.8% of poor children were fully vaccinated in the 2006, 2007, and 2008 NISs, respectively. Multivariate analyses of all 3 seasons found positive significant (all P < .05) associations between state-level Medicaid reimbursement and influenza vaccination rates among poor children. A $10 increase, from $8 per influenza vaccination (the US average) to $18 (the highest state reimbursement), in the Medicaid reimbursement rate was associated with 6.0-, 9.2-, and 6.4-percentage point increases in full vaccination rates among poor children in the 2006, 2007, and 2008 NIS analyses, respectively. Medicaid reimbursement rates are strongly associated with influenza vaccination rates.