Immunization barriers in Minnesota private practices: the influence of economics and training on vaccine timing.

Objective: Identify barriers to immunization and evaluate the timing of immunization in private practice settings.

Methods: Design was a comparison of childhood immunization data with a survey of physicians who administered the vaccines. Setting was primary care offices in rural and urban/suburban Minnesota. Subjects were children under 7 years old who were receiving either Diphtheria, Tetanus, and Pertussis vaccine, Diphtheria and Tetanus vaccine, or the first Measles, Mumps and Rubella vaccine and their primary care physicians. Main outcome measures were time from birth to the third Diphtheria, Tetanus, and Pertussis vaccine (DTP) and from birth to the first Measles, Mumps, and Rubella vaccine (MMR) and their determinants.

Results: The third Diphtheria, Tetanus, and Pertussis vaccine and first Measles, Mumps, and Rubella vaccine were late in 32% and 41% of children, respectively. We observed a significant difference, based upon insurance status, in Diphtheria, Tetanus, and Pertussis vaccine timing (p = 0.0001) but not in Measles, Mumps, and Rubella vaccine timing. Significant correlates of earlier Diphtheria, Tetanus, and Pertussis immunization include physician residency training, suburban/urban practice locale, and the likelihood that the physician would refer children based upon insurance coverage to health departments for immunization.

Conclusions: Important determinants of immunization in the private sector include reimbursement and physician training about prevention.