Impact of increased physician supply on use of health services: a longitudinal analysis in rural Minnesota.

Prevalence studies of the use of ambulatory health care services have consistently reported relatively lower demand for services in rural areas. Such studies have implied that low use rates may be fixed characteristics of rural populations and may be resistant to the influence of manipulable variables such as supply of physicians. This longitudinal study suggests that use rates are in fact significantly changed after improvement of manpower resources, but that the effects are limited to the vicinity of new practice locations.