Would better adherence to guidelines improve childhood immunization rates?
OBJECTIVE: To evaluate the contribution of three provider practices to underimmunization of children with financial coverage for vaccines. DESIGN: Retrospective cohort study of children in a large health maintenance organization, based on computerized databases and chart review. SETTING: Large health maintenance organization in northern California. PATIENTS: The population included 24,268 children who had at least one immunization recorded in the health plan tracking system and had continuous health plan membership between 15 and 24 months of age in 1992 through 1993. The study group (N = 4691) were those who had missed one or more of the immunizations due during their second year. RESULTS: Most (57%) of the underimmunized children had made at least one clinic visit between 15 and 24 months of age. Among those underimmunized children who made well care visits, 90% had been partially immunized at the visit but had not been simultaneously given all vaccines for which they were eligible.
