Effect of feedback on test ordering behaviour of general practitioners.

OBJECTIVE To assess the effect of feedback on the test ordering behaviour of general practitioners. DESIGN Comparison of requests at two diagnostic centres, and internal comparison between tests which were discussed in feedback and tests which were not. SETTING A diagnostic centre in Maastricht giving feedback and another elsewhere in the Netherlands (laboratory A) not giving feedback. SUBJECTS All 85 general practitioners in the region of Maastricht, and all general practitioners in the region of laboratory A. MAIN OUTCOME MEASURES Numbers of tests requested by general practitioners. RESULTS Requests at the Maastricht diagnostic centre decreased soon after the onset of feedback whereas there was a persistent increase in requests at laboratory A. Tests that were discussed showed the strongest decrease (maximum 40%), though tests that were not discussed decreased as well (maximum 27%). CONCLUSIONS Feedback on diagnostic requests may exert a strong influence on request behaviour. Four years after the onset of feedback the effects were still noticeable.