Primary-care--physician supply: policy analysis on the state level.

Objective: To describe a method for policy analysis on the state level for understanding frequently overlooked determinants of the current status and dynamics of primary-care-physician supply.

Design: The method used is systems analysis. The approach takes account of the changing interstate migration, tracking the professional origins of physicians, their uneven age distribution, and the considerable time delays in the system. The forecasting mathematical model consists of the physician-aging submodel, the undergraduate and graduate medical education submodel, and the migration subsystem.

Setting: The necessary data were restored fully from the Virginia Board of Medicine archive database.

Results: The analysis shows the outstanding importance of out-of-state migration for the state of Virginia: approximately two thirds of primary-care physicians are out-of-state medical graduates. In the next decade, the attrition of primary-care physicians will start to increase steadily because of the prominent bulge in the physician age distribution. Similar bulges were observed in the age distributions for some other states.

Conclusions: The method reveals the underlying mechanisms and principles of physician work-force reproduction. It may show which goals are feasible, and it may be used in any state for the research necessary for rational policy formulation.