The pay gap between male and female nurses does not appear to have narrowed in recent years.

A new analysis of the salary trends of registered nurses (RNs) in the United States between the years of 1998 and 2013 found male nurses are paid more across multiple settings and specialties, the Journal of the American Medical Association (JAMA) reported.

"Nursing is the largest female dominated profession so you would think that if any profession could have women achieve equal pay, it would be nursing," lead study author Ulrike Muench from the University of California, San Francisco told the Huffington Post.

Fifty years after the Equal Pay Act, income inequalities between genders has narrowed in many occupations, but nursing does not appear to be one of those fields. Researchers performed an analysis of this income data using the quadrennial National Sample Survey of Registered Nurses (NSSRN) and the American Community Survey (ACS), JAMA reported.

The study sample included 87,903 RNs, 7 percent of which were men; the ACS sample included 205,825 RNs, 7 percent of which were also men. The salary gap was determined to be at $7,678 for ambulatory care and $3,873for hospital settings. This gap was seen across all specialties, excluding orthopedics. The salary gaps ranged from $3,792 for chronic care to $6,034 for cardiology. 

"The roles of RNs are expanding with implementation of the Affordable Care Act and emphasis on team-based care delivery. A salary gap by gender is especially important in nursing because this profession is the largest in health care and is predominantly female, affecting approximately 2.5 million women. These results may motivate nurse employers, including physicians, to examine their pay structures and act to eliminate inequities," the authors wrote.

The findings were published in a recent edition JAMA.