Date of Award

January 2011

Document Type

Open Access Thesis

Degree Name

Medical Doctor (MD)



First Advisor

Mary Warner

Subject Area(s)

Health sciences, Public policy


An overwhelming body of health policy literature points to an impending shortage of health care providers in the United States, with special emphasis on a growing shortage of primary care providers. As such literature and similar claims made in the mass media influence political debate and government policy, it becomes necessary to determine whether the assumptions on which these predictions are based are, in fact, valid. The purpose of this study is to examine changes in primary care practice among allopathic (MD) and osteopathic physicians (DO), physician assistants (PA), and nurse practitioners (NP) over the past 20 years, specifically, how the proportion of professionals practicing in primary care specialties has changed over time. Data were obtained from previously published, publicly available reports of practice specialty among actively practicing clinicians from each of the provider types and longitudinal changes in practice specialty were characterized using descriptive statistics. The percentage of MDs practicing in primary care fields remained relatively stable over the past two decades thanks to a continuing influx of international medical graduates, while the percentage of DOs in primary care declined slightly. PAs experienced an 18-percent decrease in the percentage of total PAs in primary care practice. NPs were the only group to experience an increase in primary care with a 20-percent increase over the 20-year period. While IMGs and NPs form an increasing proportion of the US primary care workforce, PAs, USMGs, and DOs are less likely to practice in primary care than 20 years ago.