Received on July 29, 2003
Accepted on November 14, 2003

Evidence-Based Laboratory Medicine and Test Utilization

Effect of a Controlled Feedback Intervention on Laboratory Test Ordering by Community Physicians

¹ Gamma-Dynacare Medical Laboratories, Brampton, Ontario, Canada, and Department of Pathology and Laboratory Medicine, The Ottawa Hospital and University of Ottawa, Ottawa, Ontario, Canada
² Departments of Medicine and Epidemiology and Community Medicine, University of Ottawa, Ottawa, Ontario, Canada, and Clinical Epidemiology Program, Ottawa Health Research Institute, Ottawa, Ontario, Canada, and Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada

^* To whom correspondence should be addressed. E-mail: psbunting{at}ottawahospital.on.ca.

Background: Most studies of interventions to reduce laboratory test utilization have occurred in academic hospital settings, used historical controls, or have had short postintervention 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. 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 10⁶ tests in 1.48 x 10⁶ visits (2.73 tests/visit); intervention group, 3.90 x 10⁶ tests in 1.41 x 10⁶ 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.