Community Influences On More Skeptical Parents: Community Levels of Personal-Belief Exemptions May Modify Risk Factors for Parents Claiming Personal-Belief Exemptions to School Immunization Requirements in Oregon, 2006

With vaccine-preventable diseases at record lows, few studies investigate rising exemptions. After finding clusters in Oregon community-areas and studying one high-rate community, we hypothesized that exemption risk factors may vary among communities. In 2006, we surveyed 2,900 randomly-selected case and control parents of 2004-05 Oregon public and private school children after multi-staged sampling. High school-based communities (HSBCs) located within census-based locales were classified as high (>3.2%), medium (1.2-3.1%) or low (<1.2%) exemption-rate areas. Schools within HSBC-strata were selected. After mail/phone contacts, the adjusted response rate was 55%. We constructed weighted multivariate logistic models. Parents significantly more likely to get exemptions included those who agreed it is better for children to get diseases naturally [adjusted odds ratio (aOR)= 2.34, 95% CI 1.27-4.32], reported knowing someone with vaccine-hurt children [aOR=2.56; 95% CI 1.50- 4.36] or having heard or read of vaccine-hurt children [aOR=2.32; 95% CI 1.19-4.54], received naturopathic healthcare for children [aOR=2.61; 95% CI 1.01-6.71] or for themselves [aOR=2.06; 95% CI 1.19-3.55], and recalled discussing pros and cons with providers [aOR=3.50; 95% CI 1.75-7.03]. Exemptions were less likely if parents agreed that vaccine benefits outweigh risks [aOR=0.31; 95% CI 0.17-0.54] and recalled advice to get all vaccinations [aOR=0 .46; 95% CI 0.28-0.76]. Exemption-rate area-specific risk factors varied, e.g., risks among parents preferring naturopathic healthcare appeared stronger in low-rate [aOR=10.45; 4.67-23.37] versus medium-rate communities [aOR=0.91; 95% CI 0.28-2.97]. In high-rate areas, only protective factors were significant. Parents may weigh risks over benefits and be influenced by concerned parents, alternative providers, and underlying community-factors.