The impact of physician bonuses, enhanced fees, and feedback on childhood immunization coverage rates.

Objectives: The purpose of this study was to examine the effects on immunization coverage of 3 incentives for physicians--a cash bonus for practice--wide increases, enhanced fee for service, and feedback.
Methods: Incentives were applied at 4-month intervals over 1 year among 60 inner-city office-based pediatricians. At each interval, charts of 50 randomly selected children between 3 and 35 months of age were reviewed per physician.
Results: The percentage of children who were up to date for diphtheria, tetanus, and pertussis and Haemophilus influenzae type b; polio; and measles-mumps-rubella immunization in the study's bonus group improved by 25.3 percentage points (P < .01). No significant changes occurred in the other groups. However, percentage of immunizations received outside the participating practice also increased significantly in the bonus group (P < .01). Levels of missed opportunities to immunize were high in all groups and did not change over time. Physicians' knowledge of contraindications was low.
Conclusions: Bonuses sharply and rapidly increased immunization cover-age in medical records. However, much of the increase was the result of better documentation. A bonus is a powerful incentive, but more structure or education may be necessary to achieve the desired results.