Male nurses make $5,100 more on average per year than female colleagues in similar positions, researchers reported on Tuesday.
The new analysis, which included data on more than 290,000 registered nurses, also found that the pay gap had not narrowed within workplace settings and specialties from 1988 to 2013. The new study is the first to have measured gender disparities in pay among nurses over time.
“We now have pretty compelling evidence that there are pay inequalities between men and women in nursing over the past 25 years,” said Debra J. Barksdale, the director of the doctor of nursing practice program at the University of North Carolina at Chapel Hill, who was not involved with the new study.
Because most nurses are women, “you may think women have caught up or even might be ahead of men, but we find that’s not the case,” said Ulrike Muench, the lead author of the new study, which was published in JAMA, and an assistant professor of social behavioral sciences at the School of Nursing of the University of California, San Francisco.
The research team, which also included experts at the Yale School of Public Health and Vanderbilt University Medical Center, used data from two surveys. One provided a trove of employment information, like whether nurses worked in hospital or ambulatory settings and the number of years since graduation. But the National Sample Survey of Registered Nurses was discontinued in 2008.
The researchers also relied on census data for information on earnings, finding that the gap “exists and persists in a second nationally representative data set,” Dr. Muench said.
The gap varied across specialties, Dr. Muench and her colleagues found. Male cardiology nurses were paid more per year than female colleagues by roughly $6,000 on average. By contrast, male nurses in chronic care — focused on managing conditions like diabetes or asthma — made roughly $3,800 more than women in those specialties.
This new analysis found the pay disparity greatest among nurse anesthetists. About 40 percent are men, and they were paid $17,290 more on average per year than female nurse anesthetists.
The study did not address reasons underpinning the persistent gap. There could be several reasons, Dr. Muench said: Men may be better negotiators, for instance, or perhaps women more often leave the work force to raise children. Women may have a tougher time getting promoted, she said.
“A workplace may offer a bit more to the men in order to diversify,” said Diana Mason, a professor of nursing at Hunter College of The City University of New York and former editor of The American Journal of Nursing.
Still, it is possible that women earn less because of a “lingering bias that a man is more of an expert because he’s a man,” she said.
Amanda Anderson, who has been a critical care nurse for seven years, currently works for Mount Sinai Beth Israel hospital in Manhattan, where nurses are unionized, but she has also worked for other hospitals where nurses are not part of a union.
“I was surprised to read this study, because every time I’ve changed jobs or gotten an increase in pay, it had to do with my own education or certification,” she said.
Ms. Anderson, who recently became a nurse supervisor, said that as a bedside nurse she never thought to ask for a salary increase at any of the four other hospitals she worked at.
She said she had thought nursing salaries were “immune” to a gender gap. “The fact that there is a gender discrepancy even with a system that seems so regimented and some of the time has a labor component is shocking,” she said.
National Nurses United, the country’s largest union for registered nurses, with 185,000 members, estimates that only about 20 percent of the more than 1.6 million nurses nationwide who work in hospitals are unionized.
Dr. Mason said the new analysis was an opportunity for chief nurse officers to ask their employers for wage data by gender for employees in equal positions with comparable experience in order to root out bias in pay.
Peter McMenamin, a health economist and a spokesman for the American Nurses Association, commended the study. “The folks who did the study are well qualified and they have lots of data,” he said. “But my main hesitance in terms of statistics is they have fewer men.”
Only 7 to 10 percent of nurses are male, he acknowledged. But with a smaller sample, he said, “the reliability of the answers is less robust.”
“You can’t say this is all a statistical fluke,” he added. “It’s not. But there are different things that could explain some of this challenge.”
Next, the researchers aim to focus on explanations for earning gaps in nursing.