The effect of audit and feedback on immunization delivery: a systematic review.

Objective: To assess the effective of audit and feedback (A&F) on immunization delivery by health care professionals.

Design: Systematic review of published literature.

Main Outcome Measures: Changes in immunization rates.

Methods: We searched Medline between 1966 and 1997. We obtained additional studies from back-searching reference lists and the files of study collaborators. We included studies that were written in English, that included audit and feedback in at least one arm of the study, that studied universally recommended childhood or adult vaccines, and that provided immunization coverage data. Two reviewers read studies independently and abstracted using a validated checklist. Study quality was assessed using criteria standardized by the Cochrane Collaboration. Differences between reviewers were resolved by consensus.

Results: The search process resulted in 60 citations; 44 were fully reviewed and 15 met eligibility criteria. Five were randomized trials. Twelve of the fifteen studies found that A&F, alone or in combination with other interventions, were associated with improvements in immunization rates. The magnitude of the effect varied from -17% to +49% change. Study design heterogeneity precluded statistical pooling of study results.

Conclusions: The evidence available from published studies suggests that A&F alone may be an effective strategy for improving immunization rates. The number of well-conducted studies is small, and the effect is variable. Additional well-designed studies are needed to identify the independent effects of A&F, optimal format and frequency of A&F, and to examine its long-term effect on provider immunization practices and costs.