Barriers to measles and pertussis immunization: The knowledge and attitudes of Pennsylvania primary care physicians

Objectives: To understand the causes of low childhood immunization rates, physicians were interviewed about their knowledge, attitudes, and self-reported immunization practices. Methods: Trained interviewers conducted a standardized telephone survey of physicians. A random sample of Pennsylvania family physicians, pediatricians, and general practitioners younger than 65 years of age who were in office-based practices was selected from the combined listings of the American Medical Association and American Osteopathic Association. Physicians seeing greater than or equal to 5 patients per week under age 6 years, seeing a total of greater than or equal to 15 patients per week, and having greater than or equal to 50% primary care patients were eligible. Of 383 eligible physicians, 70% (268) responded. The questionnaire was designed using the Health Belief Model, immunization barriers, and input from practitioners in primary care, pediatric infectious disease, maternal/child health, and preventive medicine. Results: Respondents were more likely to refer to public vaccine clinics those children without insurance (P<.001) or with Medicaid (P<.001) than children with insurance. Almost all (>90%) respondents thought that vaccine efficacy was high and that the likelihood of serious side effects was low. However, only 37% gave estimates that corresponded with the literature regarding the likelihood of an infant with pertussis to need hospitalization. Many respondents used invalid vaccine contraindications; for instance, 37% would not administer MMR to a boy whose mother was pregnant. Many respondents (21%) would not administer four vaccines simultaneously. Conclusions: If the Healthy People 2000 goal to eliminate indigenous cases of measles is to be achieved, free vaccine supplies and increased provider education are needed.