Greater supply of primary care physicians linked to longer life expectancy, lower cause-specific mortality
The increase in life expectancy associated with an additional supply of primary care physicians was more than 2.5 times that seen with an equivalent increase of subspecialist physicians.
A greater supply of primary care physicians was associated with longer life expectancy and lower population mortality from 2005 to 2015, but the number of primary care physicians per capita in the U.S. decreased during this time period, an epidemiological study found.
Researchers used data from 3,142 U.S. counties, 7,144 primary care service areas, and 306 hospital referral regions to assess the association between primary care physician supply and changes in life expectancy and cause-specific mortality from 2005 to 2015. They compared changes in primary care and subspecialist physician supply with population and individual-level claims data linked to mortality, adjusting analyses for health care, demographic, socioeconomic, and behavioral covariates. Results were published online on Feb. 18 by JAMA Internal Medicine.
The total primary care physician supply increased from 196,014 physicians in 2005 to 204,419 physicians in 2015. However, due to overall population increases and disproportionate losses of primary care physicians in some counties, the mean density of primary care physicians decreased from 46.6 per 100,000 population (95% CI, 0.0 to 114.6 per 100,000 population) in 2005 to 41.4 per 100,000 population (95% CI, 0.0 to 108.6 per 100,000 population) in 2015, with greater losses in rural areas.
In adjusted analyses, 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 to 73.5 days), whereas an increase of 10 subspecialist physicians per 100,000 population corresponded to a 19.2-day increase (95% CI, 7.0 to 31.3 days). An increase of 10 primary care physicians per 100,000 population was also associated with reductions in cardiovascular, cancer, and respiratory mortality ranging from 0.9% to 1.4%.
Limitations of the study include the possibility of unobserved confounding and the inability to draw firm conclusions about individual-level effects of population-level associations, the authors noted. “Future investigations should 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,” they wrote.
Payment reform is key to increasing the number of physicians who choose to enter primary care training and practice, according to an accompanying commentary. “Continuing advocacy by the Cognitive Care Alliance and other entities such as the American College of Physicians, Society of General Internal Medicine, and American Academy of Family Physicians can help keep the issue of undervalued evaluation and management codes and the need for innovative payment policy solutions front and center,” the editorialists wrote.