The use of ambulatory testing in prepaid and fee-for-service group practices. Relation to perceived profitability.

To examine the influence of method of payment on ambulatory testing by internists, we compared the rate at which patients with uncomplicated hypertension were tested by 10 doctors practicing in large fee-for-service groups with that by 17 doctors in large prepaid groups. We examined the use of individual tests and asked the doctors in the fee-for-service groups what they believed about the profitability and costs of tests. After correcting for the patient's age, sex, duration of disease, and severity of disease as measured by pretreatment blood pressure, and for the doctor's year of medical school graduation, we found that 50 percent more electrocardiograms were obtained among patients in fee-for-service practices (0.69 per patient per year vs. 0.45, P = 0.006), and 40 percent more chest radiographs (0.49 vs. 0.35, P = 0.11). Fee-for-service doctors believed that both tests were associated with high profit and costs. These results suggest that the use of certain high-profit, high-cost tests is higher in large fee-for-service groups than in large prepaid groups. Although the generalizability of conclusions based on this limited study must be considered tentative, the findings suggest that it may be appropriate to consider changing the payments for tests as part of a more general reform of the fee schedules.