Association Between Medicaid Reimbursement and Child Influenza Vaccination Rates

OBJECTIVE: 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). METHODS: 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. RESULTS: 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. CONCLUSION: Medicaid reimbursement rates are strongly associated with influenza vaccination rates.