Differential Effects of a State Universal Purchase Program on Children's Immunization Rates According to Insurance Status ♦ 632

Abstract

Background: To eliminate financial barriers to immunization, North Carolina implemented a universal vaccine purchase program, in which the state purchases vaccine serum for all children and distributes it free to all participating providers. Providers may charge an established administration fee only. Objective: This study examined the impact of the UP program on immunization rates for children with different types of insurance. Methods: From a random birth-certificate sample of 4,000 children born in 1994 and 1995, parents were interviewed to obtain children's sites of medical care and insurance history. Chart abstraction was performed in all sites of preventive care; details of insurance coverage were verified with insurance companies, employers, and the Division of Medical Assistance. Results: Parent interviews were completed for 71% of eligible children; chart abstraction and insurance data were obtained for 97% of those with parent interviews. In month-by-month comparisons, children born in 1995 had immunization rates 4%-10% higher than their 1994 counterparts. By 24 months of age, 84% of the 1995 cohort had completed the primary immunization series, compared with 79% of the 1994 cohort (p<0.001). In all insurance subgroups (i.e., fully insured for well-child care, partially insured for well-child care, insured but with no well-child benefits, enrolled in Medicaid exclusively or in combination with private insurance, or having some periods of being uninsured), 1995 immunization rates were higher than 1994 rates. The biggest increases in immunization rates from 1994 to 1995 occurred for children who were privately insured with no well-child coverage, children who had periods of being uninsured, and children enrolled in Medicaid exclusively or with private insurance. More children in the 1995 cohort received all immunizations in the private sector. Conclusion: The North Carolina universal purchase program appears to have had a significant, positive impact on immunization rates, especially for children with inadequate insurance for well-child care. However, insurance status still influences the ability of children to receive immunizations on schedule.