Impact of supervision by medical teachers and in-patient test control programmes on the out-patient test utilization of residents.

The expense of clinical laboratory services and the broad variation in use of these services by doctors has led to several successful programmes to reduce the expense, particularly for in-patients. The applicability of the programmes to the care of out-patients of residents and the contribution of the interaction of the attending physician with the resident have not been formally studied. To address these issues, out-patient test utilization by first-year residents was studied both during and after an in-patient test control programme. Test utilization means how much the tests are used. It is another question whether the investigation makes any difference to patient care. The residents in the intervention group significantly reduced test utilization compared to the control group and the reductions were sustained for the duration of the study for the use of chemistry panels. Studies of the interaction of attending physicians with residents suggested that the residents' style of test utilization was the predominant one but that this style was magnified when working with an attending physician of similar or more extreme style.