More young physicians are entering the workforce than previously thought while fewer older physicians are remaining active, making the physician workforce younger on average, both now and in the future, a recent study of census data showed.
The workforce analysis, which challenges conclusions drawn from the American Medical Association (AMA) Physician Masterfile dataset that is commonly used to calculate physician workforce numbers, ultimately could indicate ways to make the Masterfile data more accurate, according to the study's lead author, Douglas O. Staiger, Ph.D., the John French Professor of Economics at Dartmouth College in Hanover, N.H.
“Workforce projections rely on accurate estimates of the current number of physicians as a starting point,” Dr. Staiger said in an interview. “Without more accurate estimates of the size and age distribution of the current workforce, projections of physician supply, requirements, and potential shortages may mislead policy makers as they try to anticipate and prepare for the health care needs of the population.”
The study, which was performed by researchers at Dartmouth College, the U.S. Congressional Budget Office, and the center for interdisciplinary health workforce studies at Vanderbilt University Medical Center in Nashville, Tenn., compared physician workforce estimates and supply projections using AMA Masterfile data with estimates and projections from the U.S. Census Bureau Current Population Survey (CPS).
The researchers sought to determine the annual number of physicians working at least 20 hours per week in 10-year age categories. Recent workforce trends were used to project future physician supply by age, the authors said.
The analysis showed that in an average year, the census data estimated 67,000 (or 10%) fewer active physicians than did the AMA's Masterfile, almost entirely because the census data found fewer active physicians aged 55 years and older. In addition, the census data estimated up to 17,000 more young physicians (those aged 25-34 years) than did the Masterfile (JAMA 2009;302:1674-80).
Projections using the AMA's Masterfile indicate there will be about 1,050,000 physicians in practice in 2020, whereas census data estimates indicate that there will be only 957,000 physicians in practice then, with a smaller percentage older than age 65.
“Delays in reporting when physicians enter and exit the workforce appear to lead to an underestimate of younger physicians and an overestimate of older physicians in the Masterfile,” said Dr. Staiger. He added that surveys such as the CPS cannot replace the Masterfile because they lack geographic and specialty detail, but they provide benchmark data that could be used to adjust estimates based on Masterfile data. These adjustments could be important as policy makers struggle to deal with workforce issues, he said.
The study was funded by a grant from the National Institute on Aging. No financial disclosures for any of the authors were reported.
In an accompanying editorial, Thomas C. Ricketts, Ph.D, a researcher at the North Carolina Rural Health Research and Policy Analysis Center in Chapel Hill, noted that the health care reform debate highlights how physician supply is linked to universal access and cost issues (JAMA 2009;302:1701-2).
“Establishing the right number of physicians is difficult if they cannot be accurately counted,” he wrote. “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.”