Association between parents' preferences and perceptions of barriers to vaccination and the immunization status of their children: a study from Pediatric Research in Office Settings and the National Medical Association.

OBJECTIVES: To assess the association between parents' perceptions of various barriers to vaccination and their preferences regarding specific strategies designed to reduce missed vaccination opportunities and the immunization status of their children and to estimate the overall contribution of the perception of barriers on underimmunization among children who are vaccinated in pediatricians' offices.
METHODS: As part of a nationwide study on the immunization status of children followed by practicing pediatricians, parents of children who were 8 to 35 months of age and seen consecutively at 177 participating practice sites completed a survey on health beliefs regarding the vaccination process. In addition to demographic information, parents were asked to identify the most difficult thing about obtaining immunizations, as well as their preferences regarding the maximum number of vaccine injections that should be administered to their child at 1 visit and for receiving a needed immunization during an office visit for a mild illness. Immunization data on study children were abstracted from the practice medical record, and specific survey responses for each parent were compared with the immunization status of his or her child at 8 months of age using chi2 tests. For parental health beliefs associated with immunization status by bivariate analyses, the relative risks for underimmunization and population-attributable risk percentages of each belief were calculated after potentially confounding variables were adjusted for.
RESULTS: Immunization data were collected on 13 520 children; 13 516 parents responded to at least 1 question regarding vaccination health beliefs. Two thirds of the responding parents indicated that their child should receive no more than 2 immunizations at 1 visit. However, there was no difference in the preferred maximum number of vaccines between parents of children who were fully immunized at 8 months of age and those of underimmunized children. Similarly, there was no difference in a stated preference for receiving a needed immunization during an illness visit. Overall, 74% of respondents indicated that there was "nothing" difficult about obtaining vaccines for their children. The most commonly cited barrier was concern about the side effects of vaccines, identified by 22.6% of parents. However, this barrier was not associated with immunization status. Each of the remaining barriers-including the confusing vaccination schedule, expense of vaccines, the inconvenience of the vaccination process, having a child who was often too ill to receive vaccines, religious objections, and other identified barriers-was statistically associated with immunization status, with adjusted relative risks for underimmunization ranging from 1.42 to 3.04. However, because each of these barriers was identified as important by <5% of parents, the population-attributable risk percentage for each was < or =2.5%. Overall, it was estimated that parental perception of barriers associated with immunization status accounts for 8.0% of the underimmunization observed among children who are vaccinated in the offices of primary care pediatricians.
CONCLUSIONS: Parental preferences regarding vaccination practices designed to reduce missed opportunities were not associated with the immunization status of their children. Although several barriers to vaccination were associated with immunization status, individual barriers were identified by a small minority of parents. Overall, parental perceptions of barriers to vaccination do not seem to be a significant cause of underimmunization in this population of children.