Spatial Accessibility to Providers and Vaccination Compliance Among Children with Medicaid

Low-income children in Washington D.C. were more likely to have received basic immunizations when living in areas with a higher availability of vaccination providers. In low-income neighborhoods, because of limited transportation options, a sparse presence of health care providers can be devastating. When low-income parents are without a means of transportation, children can miss necessary immunizations.

This study, conducted in Washington, D.C., sought to understand how the proximity of low-income families to pediatric immunization providers affected vaccination compliance among children holding Medicaid insurance. Using data from the D.C. Department of Health Immunization Information System (IIS), researchers plotted over 5,000 street addresses and created a contour map of residential density. The authors created a map of health care providers using data from multiple sources. To create a provider map that specifically addressed immunization, the authors made several adjustments using data about each provider; each provider received a weighted score that indicated the immunization services available at each point on the map.

Key Findings:

  • Overall, living near a greater number of immunization providers predicted a higher likelihood that a child would be compliant with required vaccinations.
  • Vaccination rates varied between neighborhoods from 38 percent to 53 percent.

Language barriers may affect access to care and vaccinations. The ability to identify specific neighborhoods with low vaccination rates will help tailor interventions to meet specific needs. This study adds to a collection of evidence that the physical availability of health care providers affects outcomes for a number of conditions. These conditions will be best managed with persistent, long-term care.