Provider characteristics and behaviors as predictors of immunization coverage

Background: Most studies of immunization behaviors measure adherence to standard immunization practices, relying on surveys without linking reported behaviors to objectively measured immunization rates. This study attempts to close that gap. Methods: In 1997, pediatric, family, and general providers in Pennsylvania serving children aged <36 months (N=251) completed immunization behavior surveys. We linked these responses to patient chart audits for practice-level immunization rates. Results: Immunization rates for our sample fell short of national goals (average up-to-date immunization status at 12 MONTHS=69%). They were significantly higher for pediatricians than for family/general practitioners (78% vs 58%, p<0.001) and for practices treating ≥100 children in the past 30 working days than for those treating <100 children (77% vs 62%, p<0.001). Behaviors with significant associations to higher immunization coverage were: (1) appropriately giving diptheria, tetanus toxoids, and pertussis immunization under false contraindications versus withholding it (73% vs 66%, p<0.05); (2) willingness to give at least four injections at one visit versus fewer injections (74% vs 65%, p<0.01); and (3) holding immunization in-service training versus no training (71% vs 65%, p<0.05). However, multivariate analysis showed that only provider specialty remained a significant predictor of coverage. Conclusions: Pediatricians have higher coverage rates than family/general practitioners. Although pediatricians see more children, the number of immunization-delayed children at 12 months is approximately the same for both provider groups. Therefore, efforts to improve coverage should continue to be directed toward both groups.