No exit: an evaluation of measures of physician attrition

To validate physicians' self-reported intentions to leave clinical practice and the American Medical Association (AMA) Masterfile practice status variable as measures of physician attrition, and to determine predictors of intention to leave, and actual departure from, clinical practice.

Survey of specialist physicians in urban California (1998); the AMA Physician Masterfile (2001); and direct ascertainment of physician practice status (2001).

Physicians' intention to leave clinical practice by 2001 (self-reported in 1998) was tested as a measure of each physician's actual practice status in 2001 (directly ascertained). Physician practice status according to the 2001 AMA Masterfile was also tested as a measure of physicians' actual practice status in 2001. Multivariate regression was used to predict both physicians' intentions to leave clinical practice and their actual departure.

AMA Masterfile data on 2001 practice status were obtained for 967 of 968 physician respondents to the 1998 survey. Actual practice status for 2001 was directly ascertained for 957.

The sensitivity of Masterfile practice status as a measure of actual departure from clinical practice was 9.0 percent, and the positive predictive value was 52.9 percent. Allowing for a two-year reporting lag did not change this substantially. Self-reported intention to leave clinical practice had a sensitivity of 73.3 percent and a positive predictive value of 35.4 percent as a measure of actual departure from practice. The strongest predictor of both intention to leave clinical practice and actual departure from practice was older age. Physician dissatisfaction had a strong association (OR=5.6) with intention to leave clinical practice, but was not associated with actual departure from practice.

Our findings call into question the accuracy of both AMA Masterfile data and physicians' self-reported intentions to leave as measures of physician attrition from clinical practice. Research using these measures should be interpreted with caution. Self-reported intention to leave practice may be more of a proxy for dissatisfaction than an accurate predictor of actual behavior.