No exit: an evaluation of measures of physician attrition

Health Services Research, Oct, 2004 by Diane R. Rittenhouse, Elizabeth Mertz, Dennis Keane, Kevin Grumbach

"... but what do numbers matter?"

--Garcin, the protagonist of the play No Exit, by Jean Paul Sartre

Physician supply is the product of a dynamic interplay between production of new physicians and attrition of existing physicians. Although dramatic growth in the number of graduate medical education positions in the United States in recent decades has focused workforce discussions on trends in the entry of new physicians, little attention has been paid to the "exiting" side of the physician supply equation. Several recent studies demonstrate a significant level of physician stress and dissatisfaction nationwide (Landon et al. 2002; Linzer et al. 2002; DeVoe et al. 2002; Wetterneck et al. 2002; Sturm 2002; Shugerman et al. 2001; Linzer et al. 2001; Buchbinder, Melick, and Powe 2001; Linzer et al. 2000; Frank et al. 1999), raising the possibility that physicians may be leaving clinical practice prematurely, and highlighting the need for further research in this area. This issue of potential premature attrition drew attention in California in 2001 when the California Medical Association issued a widely publicized report, And Then There Were None. Based largely on anecdotal evidence, this report suggested that a large proportion of physicians were planning to quit practice or leave California within the ensuing three years due to their disgust with the practice environment in the state (California Medical Association 2001). The Massachusetts Medical Society published a similar study in June 2002, concluding that physician retention in Massachusetts had become increasingly difficult (Massachusetts Medical Society 2002).

Other than through death, there are two main routes by which physicians exit clinical practice. The first is a change in profession, either within medicine or to another field. Although there is a growing body of research into the antecedents of job turnover among physician employees (Pathman et al. 2002; Buchbinder et al. 2001; Buchbinder et al. 1999), we found only one American study (Williams et al. 2001) and one English study (Sibbald, Bojke, and Gravelle 2003) that focused on physicians choosing to leave clinical practice altogether. The second and more traditional route of exit from clinical practice is retirement. The literature does contain some studies of antecedents of physician retirement (Sturm 2002; Davidson et al. 2001; Kmietowicz 2001; Travis et al. 1999; Davidson, Lambert, and Goldacre 1998; Wakeford, Roden, and Rothman 1986), although only two are from the United States (Kletke et al. 2000; Powell and Nakata 2001).

Data on physician attrition in the United States have traditionally derived from the American Medical Association (AMA) Physician Masterfile or from self-reported measures of physicians' intention to retire or leave clinical practice. The AMA Masterfile contains continuously updated information on all U.S. allopathic physicians and many osteopathic physicians, including those who are not AMA members. Masterfile data are used to determine age and sex specific attrition rates in the Bureau of Health Professions forecasting models and by other researchers to study retirement (Vector Research 2000). A variety of sources are used to update the Masterfile, including information from medical schools, hospitals, state licensing agencies, medical societies, and professional associations. In addition, the AMA conducts an ongoing survey of the entire physician population to collect detailed practice information, cycling through each physician every three years. These methodologies for updating Masterfile data may result in delays in posting information on physician attrition from clinical practice. Details regarding administration of the Masterfile database have been published elsewhere (Pasko, Seidman, and Birkhead 2000; Kletke et al. 2000; Baldwin et al. 2002).

Another source of data on physician attrition is the self-report of physicians' intentions to leave clinical practice. It is common to rely on "intent to ..." variables in the absence of data on actual rates of particular behaviors, and the advantages and disadvantages of such surrogate variables have been reviewed elsewhere (Dalton, Johnson, and Daily 1999). The relationship between employee intent to quit specific employment positions and actual job turnover has been extensively studied and two large meta-analyses estimate the correlation coefficient to be 0.50 (Steel and Ovalle 1984; Tett and Meyer 1993). Only two studies of physicians have attempted to validate this relationship. Buchbinder and colleagues (2001) found that primary care physicians who indicated that they were very likely to leave their current practice situation within the next two years were 2.38 times more likely to have done so on follow-up survey four years later than those who indicated that they were very unlikely to leave. Similarly, in a follow-up survey of 45 Western Australian rural physicians who indicated in 1986 that they intended to leave rural practice, Kamien (1998) found that 22 (49 percent) remained in rural practice in 1996. The relationship between intent to leave clinical practice entirely, as opposed to intention to leave a particular job position or location, and actual departure has not been studied.