U.S. Census Data Indicate Physician Workforce May Be Smaller, Younger Than Expected, Study Says

A recent Dartmouth College study that used U.S. Census Bureau data to make projections about the physician workforce concluded that the future physician workforce will be smaller and younger than indicated by projections that used the AMA's Physician Masterfile data. If this proves true, shortages of primary care physicians will be worse than projected, as will patients' access to primary care, according to an AAFP physician workforce expert.

The study, "Comparison of Physician Workforce Estimates and Supply Projections," in the Oct. 21 Journal of the American Medical Association, or JAMA, compared data gathered from 1979 to 2008 by the U.S. Census Bureau Current Population Survey, or CPS, with data from the AMA Physician Masterfile, which is an inventory of the physician supply frequently used by workforce analysts.

Projections based on both the CPS and the AMA Masterfile data indicate that the total number of active physicians in the United States will increase by about 20 percent between 2005 and 2020. That's a projected workforce of 957,000 active physicians by 2020 using CPS data or 1.05 million physicians using Masterfile data, according to the study.

In 2020, the CPS data estimate nearly 100,000, or 9 percent, fewer active physicians than do projections made using the Masterfile data. In fact, according to the study, in an average year in the sample period, the CPS estimated a total of 67,000, or 10 percent, fewer active physicians than did the Masterfile.

The discrepancy was almost entirely attributable to fewer active physicians ages 55 and older in the CPS data. According to the study, this finding could be caused by delays in updating Masterfile data when a physician retires or changes his or her specialty, location or immigration status.

When analyzed by age ranges spanning 10 years, estimates were similar for physicians ages 35-54 between both sets of data, but they differed markedly for both younger and older age ranges. Among younger physicians, the CPS, on average, estimated 9,000, or 6 percent, more active physicians ages 25-34 than did the Masterfile. And among older physicians, the CPS estimated 22,000, or 20 percent, fewer active physicians per year in the 55-64 age range than did the Masterfile. The CPS also estimated 35,000, or 51 percent, fewer active physicians per year in the 65 or older age range relative to the Masterfile.

"The CPS estimates of more young physicians were consistent with historical growth observed in the number of first-year residents, and the CPS estimates of fewer older physicians were consistent with lower Medicare billing by older physicians," the study said.

Perry Pugno, M.D., M.P.H., director of the AAFP Division of Medical Education and a physician workforce expert, told AAFP News Now that if the CPS estimates are more accurate, then predictions regarding physician shortages, especially among family medicine and other primary care physicians, could actually be worse than projected.

It means there will be a smaller pool of physicians and fewer active older physicians to take care of the nation's aging baby boomers, he said.

Although the CPS estimate puts the cohort of younger physicians at a larger number than the Masterfile, these physicians have a tendency to work fewer hours a week than their predecessors, "further exacerbating the shortage and limiting access," Pugno said.

The good thing about a larger-than-expected pool of younger physicians is that they are more likely to embrace health information technology, electronic health records and the patient-centered medical home model of care, he added.

"That won't impact the workforce imbalance and shortage of primary care physicians significantly. That will just make their practices more patient-centric and maybe a bit more efficient," Pugno said.

According to an editorial in the same edition of JAMA, "How Many Physicians? How Much Does It Matter?" author Thomas Ricketts, M.P.H., Ph.D., said questions about the two sets of data are important and continue the debate about the supply of physicians and whether that number meets U.S. health care needs.

Current health care reform bills include ways to adjust the physician supply and distribution through incentives targeted to expand the number of primary care practitioners or to attract physicians to rural and underserved areas, said Ricketts.

In fact, he noted, the physician workforce is a critical factor in health care reform efforts and discussions. "Having accurate estimates for determining not only the number of physicians, but also current and future physician workforce requirements and capabilities for delivering primary and specialty care will be essential for achieving and sustaining effective health care reform," Ricketts said.