Childhood immunization coverage in US states: the impact of state policy interventions and programmatic support.

Although research suggests numerous interventions that can improve immunization coverage (Taskforce on Community Preventive Services, 2000), there is often a gap between policies supported by and public entities. The question for this study is whether the variation in childhood (19 to 35 months) immunization coverage rates across states is related to significant variations in state regulatory regimes that may optimize the benefits of state registries and systems that are designed to improve assessment of immunization practices. Utilizing 2002 data from the CDC and survey data collected from state immunization program officials, we find that financial support for state immunization programs, opt-out state registries, and state-mandated participation in provider quality improvement and assessment programs have positive associations with statewide coverage rates. We also suggest that more active state governmental support for interventions supported by rigorous scientific evaluation will not only improve early childhood immunization coverage, but may also support other public health objectives such as life-time full immunization and improve bioterrorism response planning.