A reexamination of the use of physician services: the role of physician-initiated demand.

Most studies of the use of physician services have focused on characteristics of the patient to explain variations in use. This study employed data from the National Medical Care Expenditure Survey to analyze differences in the use of physicians for ambulatory care and the extent to which these differences were attributable to the physician, the patient, or both. Where differences in patients' out-of-pocket expenses and the physician/population ratio existed, physicians proved to be the sole source of utilization differences. Overall, physicians were found to be motivated primarily by medical rather than financial concerns.