Trial of strategy for reducing the use of laboratory tests.

Clinical guidelines and a weekly review of medical records were introduced into a medical unit in a teaching hospital to promote a more discriminating use of laboratory tests. This strategy resulted in an immediate reduction in the average number of requests each week from 74 to 27 haematological tests (64%) and 158 to 58 biochemical tests (64%). During a period of 10 weeks after the strategy was introduced (the intervention period) the mean number of haematological tests for each person decreased from 2.0 during the baseline period to 1.1 (45% reduction; p less than 0.01) and the mean number of biochemical tests decreased from 4.4 to 2.7 (39%; p less than 0.0001). The decrease in the number of repeat requests was greater than that for new requests and accounted for half the reduction in use. There was no significant change in the number of tests requested from an adjacent medical unit that was not exposed to the interventions. This strategy is worthy of trial in other specialties and hospitals, but attention will have to be paid to possible difficulties in sustaining reductions in use over long periods of time.