Immunization registries in the United States: Implication for the practiceof public health in a changing health care system

Although immunization rates among children are rising across the country, r ates in inner-city areas have remained at similar to 50%-60%, less than or equal to 30% lower than corresponding suburban or state immunization levels . The failure to raise immunization levels in poor, underserved populations is caused in part by the lack of timely and accurate child-specific immuni zation information for providers and parents. Immunization registries are a new tool in health care that can be used to address these and other barrie rs to effective immunization delivery. Moreover, immunization registries ha ve the potential to help health care officials track and improve delivery f or a broad range of important child health services. An immunization regist ry is a computerized database of information on children (usually preschool -age children) in a defined population (e.g, those enrolled in a health mai ntenance organization or living in a specific geographic area), which is us ed to record and track all immunizations received by each child. The regist ry receives the information primarily from public and private providers tha t administer immunizations, as well as from parents, schools, and other age ncies. A fully functioning immunization registry can be used to identify in dividual children in need of immunizations and to report on immunization ra tes by population characteristics such as child age, assigned provider, or geographic area (e.g, neighborhood, city). Today, >250 local public health departments have immunization registries that are in various stages of plan ning or development. Only a small number of these registries meet the minim um functional criteria of maintaining records on 95% of all eligible 2-year -old children in the target population and providing an electronic immuniza tion record that is accessible to providers. Nascent immunization registrie s represent innovative technologic solutions to the challenge of monitoring health problems and health care access on a population basis. This is a fu ndamental activity of public health agencies, but one that is increasingly shared by large health maintenance organizations. The study of the developm ent of immunization registries across the United States provides an importa nt case study for how public health agencies will use the rapidly developin g health information infrastructure to perform health assessment and health assurance activities in a managed care environment.