A survey of mid-career academic physician researchers finds that gender differences in salary exist, even after adjustment for differences in specialty, institutional characteristics, academic productivity, academic rank, work hours, and other factors, according to a study in the June 13, 2012 issue of the Journal of the American Medical Association (JAMA).

“Studies have revealed gender differences in physicians’ pay, but experts continue to debate the magnitude and cause of these differences. Some evidence suggests that disparities in pay are explained by specialization, work hours, and productivity, leading some to believe that they are justifiable outcomes of different choices made by men and women,” says a JAMA press release . “Debate persists in part because most studies of physicians’ pay have included relatively heterogeneous groups, are now dated, or are limited by lack of information on key factors such as specialty or family characteristics,” according to background information in the article. “It is unclear whether male and female physician researchers who perform similar work are currently paid equally.”

Reshma Jagsi, MD, DPhil, of the University of Michigan, Ann Arbor, and colleagues conducted a study to examine whether salaries differ by gender in a relatively homogeneous group of physician researchers and, if so, to determine if these differences are related to differences in specialization, productivity, or other factors. For the study, a U.S. nationwide postal survey was sent in 2009-2010 to recipients of National Institutes of Health (NIH) K08 and K23 career development awards in 2000-2003.

The researchers focused on this select population to minimize variability in aptitude or motivation, as well as in seniority and content of work activities. Eligibility for the analysis was limited to physicians who continued to practice at United States. academic institutions and reported their current annual salary. The analysis included 247 female and 553 male physicians whose average age was 45 years.

The researchers found that overall, the average salary was $167,669 for women and $200,433 for men in this sample. In the final model, male gender was associated independently and significantly with higher salary (+$13,399), even after adjustment for specialty, academic rank, leadership positions, publications, and research time. Additional analysis suggested that the expected average salary for women, if they retained their other measured characteristics but their gender was male, would be $12,194 higher than observed.

The authors also found that women tended to be in lower-paying specialties, with 34 percent of women and 22 percent of men in the lowest-paying category, and 3 percent of women and 11 percent of men in the highest-paying category. In addition, women were less likely to hold administrative leadership positions (10 percent vs. 16 percent) and had fewer publications (average, 27 vs. 33 publications) and work hours (average, 58 vs. 63 hours).

“Ultimately, this study provides evidence that gender differences in compensation continue to exist in academic medicine, even among a select cohort of physician researchers whose job content is far more similar than in cohorts previously studied, and even after controlling extensively for specialization and productivity. Efforts to investigate the mechanisms by which these gender differences develop and ways to mitigate their effects merit continued attention, as these differences have not been eliminated through the passage of time alone and are difficult to justify,” said Dr. Jagsi.