By Dr. Luca Valle and Dr. Ann Raldow

Conversations surrounding pervasive inequities in all aspects of the workforce are now having their long overdue moment in the spotlight of American society, and healthcare is no exception.

Paradoxically, perhaps because the field of medicine attracts a select group of forward-thinking, emotionally intelligent, and logical people motivated to help others, many have been lulled into believing that gender disparity in medicine does not exist, or when it does, it exists for purely rational reasons. For example, while numerous studies have described the trend of men earning more than women at many stages of their careers, these differences are often attributed to different career choices made by men and women in medicine, including the decision to enter less remunerative specialties and work fewer hours.

Yet, other high-impact studies led by Dr. Reshma Jagsi and colleagues have suggested this may not be the case, since substantial unexplained salary gaps have been proved to persist even after adjusting for specialty, academic productivity, and work hours.

Within the field of radiation oncology, gender has been shown to influence many aspects of a physician’s career, including opportunities for academic advancement, scholarly activity, invitations to participate in scientific panels, funding for physician researchers, and even disease sites treated.

As a new trainee in radiation oncology who has always had an interest in understanding and mitigating inequities as they manifest in healthcare, I was curious as to how gender might be influencing salary and clinical activities in our field. Shortly after starting residency at the University of California Los Angeles, I sought out the mentorship of Dr. Ann Raldow, who is a member of the UCLA Jonsson Comprehensive Cancer Center, and we set out to tackle the question of whether a disparity existed in clinical activities and reimbursement in the field of radiation oncology.

We were both rather surprised to find that female radiation oncologists submit fewer charges to Medicare, are reimbursed less per charge submitted and receive lower Medicare payments overall in comparison to male radiation oncologists.

Our study was designed by querying a large database called the Physician and Other Supplier Public Use File (POSPUF). This database was created to increase financial transparency in the United States healthcare system by tracking data on individual physician reimbursements from Medicare. This allowed us to formally and objectively characterize productivity and reimbursement patterns among male and female radiation oncologists on a national level for the first time.

We looked at payments in both non-facility-based (or freestanding, often private practice) radiation oncology clinics, as well as facility-based (or hospital-based, often academic) radiation oncology clinics, since distinctions in billing practices would cause any reimbursement in the non-facility-based setting to be higher due to the collection of technical fees by physicians who own the machines used to deliver radiation.

Delving into the details of the study, what we found was that of the 4,393 radiation oncologists submitting claims to Medicare, female physicians who worked in a non-facility-based setting submitted an average of 1,051 fewer charges and collected $143,610 less in revenue than male physicians. Female radiation oncologists working in a facility-based setting submitted on average 423 fewer charges and collected $26,735 less in professional revenue than their male counterparts.

These discrepancies were even wider when making comparisons in the group of radiation oncologists submitting the most Medicare claims. Even among similarly highly productive radiation oncologists, female radiation oncologists in the facility-based setting collected on average $33,026 less than their male counterparts. In the non-facility-based setting, this gap was predictably wider, with similarly highly productive females collecting an average of $345,944 less than males.

It is important to note that observational studies such as ours cannot establish an exact cause for the differential practice and reimbursement patterns we report, but speculating on some of their driving factors is an important next step in determining how we might level the playing field.

The first question to ask is: are these differential findings even related to gender at all? It seems like an unavoidable conclusion, but it is possible that there are other extraneous factors that we did not control for in our study that are driving these results more significantly than provider gender.

If, however, gender is indeed influencing our findings, either directly or indirectly, this may be rooted in several factors. In terms of clinical activity, less clinical activity may be a natural consequence of the value-based labor choices that female practitioners make, particularly within a gender-structured society where women continue to be expected to shoulder the greater share of domestic responsibilities. However, less activity might also be tied to overt sexual discrimination leading to fewer referrals from surgical and medical oncologists. It is also possible that in designing their clinic schedules, women prioritize time spent with a given patient over number of patients seen, and that prioritizing quality over quantity results in fewer claim submissions to Medicare. And finally, there may be less billing support in practices attracting female providers, thereby resulting in a failure to capture services that are actually being provided.

In terms of reimbursement, decreased collections for women might be the natural consequence of gender-related decreases in clinical activity described above. However, decreased volume of claim submission alone is insufficient to explain the gap in reimbursement, particularly when you consider our finding that women also collect less per charge despite the fact that Medicare reimburses male and female providers at the same rates. This is likely due to women submitting different kinds of codes than men, and the codes women submit are likely less well-remunerated. Many female radiation oncologists, perhaps for reasons of mentorship and patient demographics, elect to treat breast and gynecologic malignancies, and both of these subfields of radiation oncology rely primarily on 3D conformal technologies and brachytherapy techniques that are on the lower end of the reimbursement spectrum in terms of planning and delivery codes. Additionally, value-driven management decisions based on the communal attributes socialized into women (versus the agentic attributes socialized into men) could partially explain a payment differential. For example, when two equivalent treatment options are available, it is possible that female radiation oncologists are more likely to select the more cost-effective option. We have seen this in other specialties, where women have been shown to adhere more closely to clinical guidelines, forego costly interventions, and engage in shared-decision making with patients more frequently. And finally, since many of the most senior radiation oncologists in our field are male, decreased seniority in practice hierarchies could be resulting in fewer lucrative referral patterns for the less senior female radiation oncologists.

In order to help distinguish amongst these potential etiologies, we plan to look at the claims submitted by men and women over this same time period to determine if there is a difference in the types of services that men and women bill for. We also plan to dig a little bit deeper into the population of physicians who collect the most Medicare dollars to see if we can learn anything about how billing patterns differ between men and women among those collecting the highest reimbursements from Medicare. The answers to some of these questions will be presented at our society’s annual meeting (ASTRO) later this year in Chicago.

There are a number of action items for healthcare executives and administrators looking for ways to mitigate this disparity. Ensuring that adequate billing support is available to all providers is key, as is assuring that there are no significant imbalances in referral networks. These are relatively quick and easy interventions that can make an impact while efforts continue to pinpoint the source of the variation. A more complex yet critical challenge is cultivating a workforce culture where women are perceived as key members of the treatment team and valued as equals, as this will help mitigate disparities both within economic reimbursement and beyond.

It is our hope that these next steps will move us closer to understanding and deconstructing sex-based barriers for economic advancement within the specialty of radiation oncology and we look forward to making important strides in this direction.

We would like to acknowledge the expertise and input of the other co-authors on this study, including Julius Weng, M.D.; Reshma Jagsi, M.D. DPhil; Fang-I Chu, Ph.D.; Sumayya Ahmad, M.D.; and Michael Steinberg, M.D.

About the authors: Luca Valle, M.D., is in his second year of training as a radiation oncology resident at UCLA. His research focuses on health policy, healthcare disparities, and health services. He is a graduate of Dartmouth Medical School and is a member of the American Society for Radiation Oncology. Ann Raldow, M.D., MPH, is an assistant professor in the Department of Radiation Oncology at the David Geffen School of Medicine at UCLA. She also is a member of the UCLA Jonsson Comprehensive Cancer Center's Cancer Control and Survivorship Program. Dr. Raldow's research focuses on therapeutic decision making, cost-effective care, quality of life and health outcomes assessments.