Effect of a controlled feedback intervention on laboratory test ordering by community physicians.

Background: Most studies of interventions to reduce laboratory test utilization have occurred in academic hospital settings, used historical controls, or have had short post intervention follow-up. Interventions with the greatest impact use multiple approaches, are repeated regularly, include comparisons with physician peers, and have a personal approach. We determined whether laboratory test utilization by community physicians could be reduced by a multifaceted program of education and feedback.

Methods: We identified 200 physicians who ordered the largest number of common laboratory tests during 1 year in a nonhospital, commercial community (reference) laboratory. They were assigned to intervention and control groups (100 each). Intervention physicians were visited individually up to three times by laboratory representatives over a 2-year period. At each visit, educational material and the physician's personal laboratory test utilization data were presented and discussed briefly in general terms, with the latter compared with utilization data for the physician's peers. Overall test utilization rates 1 year before, during, and 2 years after the intervention were measured using population-based databases. Time-series analysis was used to determine the effect of the intervention on laboratory test utilization.

Results: The two groups began with similar test utilization: control group, 4.06 x 10(6) tests in 1.48 x 10(6) visits (2.73 tests/visit); intervention group, 3.90 x 10(6) tests in 1.41 x 10(6) visits (2.77 tests/visit). During the 2-year intervention, intention-to-treat analysis showed that utilization decreased significantly in the intervention group compared with the controls [relative reduction of 7.9% (P <0.0001); absolute reduction of 0.22 tests/visit (95% confidence interval, 0.20-0.24)]. This difference persisted until the end of study observation, or more than 2 years after the intervention ended.

Conclusion: A multifaceted education and feedback strategy can significantly and persistently decrease laboratory utilization by practicing community physicians.