Although the total number of primary care physicians increased from 2005 to 2015, disproportionate losses across counties and general population increases have created an imbalance that may affect life expectancy, according to a study of U.S. population data and individual-level claims data linked to mortality.
“Sanjay Basu, MD, PhD, of Stanford (Calif.) University and his coauthors. The study was published online in JAMA Internal Medicine.
suggesting that observed decreases in primary care physician supply may have important consequences for population health,” wrote lead authorDr. Basu and his colleagues gathered data from 3,142 U.S. counties, 7,144 primary care service areas, and 306 hospital referral regions over a 10-year period to determine whether primary care physician supply was correlated with changes in life expectancy and cause-specific mortality. They found that, from 2005 to 2015, the total number of primary care physicians increased from 196,014 to 204,419. However, mean primary care physician supply decreased from 46.6 per 100,000 population (95% confidence interval, 0.0-114.6 per 100,000 population) to 41.4 per 100,000 (95% CI, 0.0-108.6).
In the researchers’ fully adjusted models, an increase of 10 primary care physicians per 100,000 population was associated with a 51.5-day increase in life expectancy (95% CI, 29.5-73.5 days; 0.2% increase). This effect was more favorable than the foreseen result of a similar increase of 10 specialist physicians per 100,000 population, which was associated with a 19.2-day increase in life expectancy (95% CI, 7.0-31.3).
Almost 300 (296) counties had no primary care physicians in 2015, while 128 counties had more than 100 per 100,000 population. On average, rural areas saw a larger decrease than urban areas (–7.0 per 100,000 population vs –2.6 per 100,000 population). Primary care physician supply did not disproportionately decrease by county poverty level or racial/ethnic demographics.
The coauthors shared their study’s limitations, including the use of private insurance data to conduct individual-level analyses and the possibility for unobserved confounding. However, they also noted that their results reinforced earlier findings on primary care physician density and overall life expectancy, calling for “future investigations [to] acquire data on the quality and comprehensiveness of primary care, types of primary care physician training and service delivery offerings, and effective access rather than just supply.”
The study was supported by the National Institutes of Health; data was accessed through the Stanford Center for Population Health Sciences Data Core, which is supported by the National Center for Advancing Translational Sciences and by Stanford University. One author reported being a senior adviser at the Center for Medicare & Medicaid Innovation; another reported being an adviser to Bicycle Health. No conflicts of interest were reported.
SOURCE: Basu S et al. JAMA Intern Med. 2019 Feb 18. doi: 10.1001/jamainternmed.2018.7624.