PURPOSE:Little is known about whether different types of physician and nonphysician primary care clinicians vary in their propensity to care for underserved populations. The objective of this study was to compare the geographic distribution and patient populations of physician and nonphysician primary care clinicians.

The effect of different methods of remuneration on the behaviour of primary care dentists.

Objective. 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. Data Sources. Survey of specialist physicians in urban California (1998); the AMA Physician Masterfile (2001); and direct ascertainment of physician practice status (2001). Study Design. 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. Data Collection/Extraction Methods. 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. Principal Findings. 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. Conclusions. 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.

The importance of oral health for overall well-being cannot be overstated. Yet the US dental delivery system struggles to address effectively the two most common oral diseases (caries and periodontal disease), which are among the most prevalent of all chronic diseases and are largely preventable. This article describes the evolution of contemporary US dental care policy and practice, highlighting the challenges resulting from the dental system's separation from the rest of health care, and explores the implications of this divide for the future of oral health policy and system reform. It remains unclear whether twenty-first-century dental science, information technology, interprofessional practice, and population health needs can be mounted onto the current nineteenth-century dental care delivery model. At stake is whether reform efforts will lead to a reduction in disparities and the widespread incidence of dental disease, or whether those efforts will maintain a system in which poor oral health serves as a primary marker of social inequality for the next generation of Americans.