(Reuters Health) - Women doctors who specialize in using radiation to treat cancers collect less in Medicare reimbursement dollars than their male counterparts, even when they see similar numbers of patients, according to a new study.

Depending on the setting, female radiation oncologists collected an average of $27,000 to $143,000 less than their male counterparts in 2016, the authors report in JAMA Network Open.

“Armed with the knowledge that disparity exists, we are better positioned to understand . . . and work toward leveling the playing field,” said lead study author Dr. Luca Valle of the University of California, Los Angeles.

Failure to address barriers to economic advancement in radiation oncology may weaken the specialty by discouraging women from entering it, he told Reuters Health by email.

Valle and colleagues analyzed 2016 data from the Centers for Medicare and Medicaid Services on payments made to 4,393 radiation oncologists, of whom 1,133 were women.

Overall, in non-facility-based practices, such as outpatient clinics and federally qualifying health centers, radiation oncologists billed nearly 9 million charges using 447 billing codes and received over $1 billion from Medicare. Men made 82.1 percent of the charges and collected 82.8 percent of the payments. Women made fewer charges and used an average of 1.32 fewer billing codes than men, which translated to women collecting about $8.50 less per charge than men.

In facility-based settings such as hospitals, radiation oncologists overall billed about 4.5 million charges with 342 billing codes and received $288 million in Medicare payments. Women, on average, made fewer charges, used 1.28 fewer billing codes and collected about $1.30 less per charge than men.

When the study team looked at productivity in terms of the number of charges submitted to Medicare, 46 of the 397 most productive radiation oncologists in facility-based settings were women, as were 54 of the 326 most productive in non-facility-based practices. In both settings, the most productive women still collected an average $176,885 less per year than equally productive men.

“Even among physicians who were equally highly productive in terms of seeing patients and submitting claims to Medicare, male radiation oncologists still earned significantly more than female radiation oncologists,” Valle said.

The differences suggest that women submit fewer or different types of charges than men, resulting in lower Medicare total reimbursements, the authors note.

Valle and colleagues next plan to study whether there is a difference in the types of services that are billed and if billing patterns are different among men and women. It may indicate whether women spend more time with patients, select more cost-effective treatment options or use fewer well-reimbursed technologies, the study authors write. Or, it could indicate a referral bias that leads to women receiving fewer cases.

“In a field where we’re trying to close the pay gap, there are multiple factors for why those pay gaps exist,” said Dr. Stephanie Terezakis of the University of Minnesota in Minneapolis, who wasn’t involved in the study.

“What it really comes down to is not a snapshot in time of a salary but what this disparity means over an entire career,” she said in a phone interview. “What does this mean for your benefits and retirement, which are then compounded over time?”

If future studies can pinpoint differences in charges and billing codes among men and women, medical schools and healthcare institutions may be able to better train new doctors to submit consistent paperwork for reimbursements.

“This has continued implications for gender inequity across a spectrum of jobs and how women are treated in the workplace,” Terezakis said. “People talk about the glass ceiling, but in reality, it’s hard to break that if you start off with completely different footing and a disadvantage.”

SOURCE: bit.ly/2V08qZE JAMA Network Open, online March 22, 2019.