The emerging physician-scientist workforce: demographic, experiential, and attitudinal predictors of MD-PhD program enrollment.

Since the inception of the National Institute of General Medical Sciences (NIGMS) Medical Scientist Training Program (MSTP) in 1964 with programs at three medical schools,1 the number of MD-PhD programs, both MSTP-funded and non-MSTP-funded, has steadily increased. In 2011, MD-PhD dual-degree programs were offered at 111 of the 131 medical schools in the United States.2 In the 2012–2013 fiscal year, there were 43 MSTP-funded programs,3 and about two-thirds of MD-PhD graduates of U.S. medical schools accredited by the Liaison Committee on Medical Education (LCME) were graduates of schools with MSTP-funded MD-PhD programs.4 Longitudinal studies of MD-PhD programs have demonstrated that many MD-PhD graduates pursue biomedical research careers.1,5 The number of students enrolled in MD-PhD programs has steadily increased over the past decade,6 and MD-PhD graduates comprised 3.2% (547/16,838) of all LCME-accredited U.S. medical school graduates in 2009.7 The Biomedical Workforce Working Group of the National Institutes of Health (NIH) Advisory Council to the Director estimated that, based on National Science Foundation Survey of Earned Doctorates data, about 9,000 individuals graduated with biomedical sciences doctoral degrees in the United States in 2009.8 Of those, 6.1% (547) graduated with an MD-PhD.7 Thus, MD-PhD program graduates in the United States still comprise only a small proportion of all MD-degree graduates and of all biomedical PhD-degree graduates. MD-PhD dual-degree holders (MD-PhDs), including some individuals who obtained their MD and PhD degrees from separate programs (i.e., not MD-PhD dual-degree programs), have been overrepresented among grant applicants and among successful applicants for NIH individual research awards.9,10 MD-PhDs also are relatively overrepresented in academic medicine and have particularly favorable career trajectories in this setting.11,12 As MD-PhDs comprise a particularly successful group of biomedical researchers, identifying the characteristics associated with MD-PhD program enrollment may help address current concerns about the size and composition of the biomedical research workforce.13,14 Thus, we sought to identify demographic, academic preparation, research experience, and attitudinal variables associated with MD-PhD program enrollment at medical school matriculation. We hypothesized that, among students who considered careers in medicine, as evidenced by their completion of the Association of American Medical Colleges’ (AAMCs’) Pre-Medical College Admission Test (MCAT) Questionnaire (PMQ),15 those students who enrolled in MD-PhD dual-degree programs would have demonstrated a longstanding commitment to biomedical research through their participation in research opportunities at multiple points along the educational continuum. Since MSTP-funded MD-PhD programs seek to recruit a demographically diverse group of trainees,16 as do LCME-accredited U.S. medical schools in general,17–19 we also hypothesized that the representation of women and of students from racial/ethnic groups historically underrepresented in the biomedical research workforce (e.g., blacks, Hispanics, and Native Americans/Alaskan Natives) enrolled in MD-PhD programs would be relatively high compared to their representation among PMQ respondents who did not enroll in medical school but similar to their representation among students who entered other MD-degree programs.