Barriers to immunization in a relatively affluent community

Background: Although Healthy People 2000 calls for the complete immunization of at least 90% of children by age 20 months, few communities can claim such success. We wanted to determine the parent-reported barriers associated with underimmunization of infants in a relatively affluent midwestern population. Methods: We undertook a case-control study of a population-based sample of parents and guardians of children who were either fully immunized or underimmunized at 20 months of age in Olmsted County, Minn. Results: In this study, 596 of 1,216 parents (46%) of both immunized and underimmunized children participated. Of these participants, 281 (47%) reported barriers to immunizations, but only 15 (3%) reported major barriers. Whereas the most commonly reported barriers were barriers of inconvenience (waiting too long, inconvenient office hours), only delays caused by a sick child, fear of reactions, trouble remembering an appointment, not knowing when the next shot was due, and transportation problems were significantly associated with underimmunization when controlling for demographic factors. Fear of reactions, sick child delays, and not knowing when the next shot was due had the highest attributable risk for underimmunization. Taken together, parent-reported barriers and demographic factors explained less than 30% of the underimmunization status of children. Parents' most common recommendations for improving immunization status were the use of a recall or reminder system and a single unified schedule for immunizations. Conclusions: In this relatively affluent community, barriers to immunization were commonly reported but few (fear of reactions, sick child delays, and not knowing when the next shot was due) were associated with underimmunization. The types of barriers reported were similar to those reported in other communities, but unlike many populations studied, cost was not reported as an important barrier.