| identifying risk factors for underimmunization by using geocoding matched to census tracts: a statewide assessment of children in hawaii. | obtaining childhood immunization coverage data for small geographic areas is difficult and resource-intensive, especially in the absence of comprehensive immunization registries. to identify factors that are associated with delayed immunization, we collected school-entry immunization records statewide and used geocoding to link to publicly available census tract sociodemographic data. | 2007 | 17682037 |