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Where Are the Women in Radiation Oncology? A Cross-Sectional Multi-Specialty Comparative Analysis

Open AccessPublished:June 02, 2021DOI:https://doi.org/10.1016/j.adro.2021.100735

      Abstract

      Purpose

      We aimed to evaluate the growth of women within the general radiation oncology (RO) workforce in comparison to the growth among other medical specialties. We also sought to create a predictive model for gender diversity to guide future recruitment efforts.

      Methods and Materials

      We identified 16 medical specialties, including RO, for analyses. We used data from the Association of American Colleges and assessed female representation at 4 time points (2006, 2011, 2016, and 2020). Additionally, we determined characteristics of medical specialties that were predictive of increased gender diversity. We performed univariate statistical analysis with linear regression to evaluate factors predictive of greater gender diversity among the medical specialties in our cohort.

      Results

      The proportion of women within the represented specialties increased over time. Obstetrics/gynecology (14,750 [2006], 23,921 [2020]; 18.7% absolute growth) and dermatology (3568 [2006], 6329 [2020]; 15.1% absolute growth) experienced the highest absolute growth in female representation between 2006 and 2020. When assessing changes between various time points in RO, the absolute change in female physicians increased by 1.5% between 2006 and 2011, by 2.2% between 2011 and 2016, and by only 0.4% between 2016 and 2020, which was the lowest growth pattern relative to the other 15 specialties. Factors predictive of gender diversity among specialties were lower average step 1 scores (P = .0056), fewer years of training (P = .0078), fewer work hours (P = .046), the availability of a standard third year clerkship for a given specialty (P = .0061), and a high baseline number of female physicians within a specialty (P = .0078). Research activities (P = .099) and interest among matriculating medical students (P = .28) were not statistically significant.

      Conclusions

      The percentage of women in RO lags behind other medical specialties and has been notably low in the last few years. Interventions that incorporate novel initiatives proposed within this study may accelerate current recruitment milestones.

      Introduction

      At the conclusion of the 1981 academic year, only 25% of graduating medical students in the United States were women.

      AAMC. AAMC diversity and inclusion: Diversity in medicine: Facts and figures 2019. Available at: https://www.aamc.org/data-reports/workforce/interactive-data/figure-12-percentage-us-medical-school-graduates-sex-academic-years-1980-1981-through-2018-2019. Accessed April 9, 2021.

      However, in 2019, the matriculating class of medical students was composed of more women than men (50.5%).

      AAMC. The majority of U.S. medical students are women, new data show. Available at:https://www.aamc.org/news-insights/press-releases/majority-us-medical-students-are-women-new-data-show. Accessed April 9, 2021.

      Despite closure of the gender gap among medical school matriculants, asymmetrical distribution of female residents and attending physicians across medical specialties persists.
      • Jagsi R
      • Griffith KA
      • DeCastro RA
      • Ubel P
      Sex, role models, and specialty choices among graduates of US medical schools in 2006-2008.
      Several factors have likely influenced this trend, including personal preference, prior exposure to a specialty, and mentorship, among other considerations.
      In radiation oncology (RO) and among other historically male-dominated specialties, there have been growing efforts to increase the presence of women in the physician workforce and to eliminate barriers to mentorship and leadership.
      • Lightfoote JB
      • Fielding JR
      • Deville C
      • et al.
      Improving diversity, inclusion, and representation in radiology and radiation oncology part 2: Challenges and recommendations.
      • Dageforde LA
      • Kibbe M
      • Jackson GP
      Recruiting women to vascular surgery and other surgical specialties.
      • Moak TN
      • Cress PE
      • Tenenbaum M
      • Casas LA
      The leaky pipeline of women in plastic surgery: Embracing diversity to close the gender disparity gap.
      • Odei BC
      • Gawu P
      • Bae S
      • et al.
      Evaluation of progress toward gender equity among departmental chairs in academic medicine.
      • Knoll MA
      • Glucksman E
      • Tarbell N
      • Jagsi R
      Putting women on the escalator: How to address the ongoing leadership disparity in radiation oncology.
      With the exception of a few studies
      • Ahmed AA
      • Hwang W-T
      • Holliday EB
      • et al.
      Female representation in the academic oncology physician workforce: Radiation oncology losing ground to hematology oncology.
      ,
      • Deville C
      • Hwang W-T
      • Burgos R
      • Chapman CH
      • Both S
      • Thomas Jr, CR
      Diversity in graduate medical education in the United States by race, ethnicity, and sex, 2012.
      highlighting variance in gender distribution between RO and other specialties, the majority of studies addressing gender concerns and reparative interventions in RO have often focused solely on female underrepresentation in RO
      • Chapman CH
      • Hwang W-T
      • Deville C
      Diversity based on race, ethnicity, and sex, of the US radiation oncology physician workforce.
      and have thus lacked the benefit of objective comparison with other medical specialties.
      In this study, we seek to provide a contemporary evaluation of the growth of women within the RO workforce compared with other specialties between 2006 and 2020 and assess if promising gains in gender diversity have been achieved within RO.

      Methods and Materials

       Study data

      This was an institutional review board exempt, cross-sectional study. We obtained workforce data from the Association of American Colleges on 16 of the largest medical specialties with varying proportions of female presence.

      AAMC. AAMC data and reports. Available at: https://www.aamc.org/data-reports. Accessed April 9, 2021.

      The data encompassed physician gender, medical specialties, and the number of practicing physicians and were reported for 2006, 2011, 2016, and 2020. We used these time points as a surrogate for trends over time, akin to similar approaches in literature.
      • Khan MS
      • Mahmood S
      • Khan SU
      • et al.
      Women training in cardiology and its subspecialties in the United States: A decade of little progress in representation.
      Physician data used in this study included those in the following settings: office-based patient care, hospital-based resident, hospital-based physician staff, administrative staff, medical teaching, research, locum tenens, or a hybrid position.
      To create a model to predict gender diversity among specialties, the authors evaluated characteristics of specialties (years of specialty training, weekly work hours, baseline gender distribution within specialties), parameters affecting residency acceptance (average step 1 scores and research activities), and factors influencing exposure to a medical specialty (standard third year clerkship and interest of matriculating medical schools).
      We obtained data from the Association of American Colleges on standard third year clerkship rotations in medical schools, length of postmedical school training per specialty, average weekly work hours per specialty, and interest in a specific specialty by matriculating medical students. Finally, we obtained data from Charting Outcomes from 2020 on average step 1 scores per specialty and the number of research activities of accepted candidates.
      We performed univariate statistical analysis to evaluate factors predictive of greater gender diversity among medical specialties in our cohort. Linear regression models were used to examine associations between covariates and outcome. In addition, t test for regression slope was conducted. A 2-sided P value < .05 represented statistical significance.

      Results

      The total number of women in our cohort of 16 specialties (Table 1) stratified by the 4 time points were as follows: 2006 (146,344; 29.8%), 2011 (176,517; 33.5%), 2016 (203,169; 37.0%), and 2020 (224,859; 39.2%). Collectively, primary care specialties constituted the highest absolute number of women in our cohort over time.
      Table 1Distribution of women among medical specialties in 2006 and 2020
      SpecialtiesNumber of women (2006)%Number of women (2020)%Absolute difference
      n = 146,344n = 224,859(%)
      Pediatrics27,76153.538,4056464.3
      Obstetrics and gynecology14,75040.923,9216059.6
      Dermatology356835.863295151
      Psychiatry11,76031.314,5704040
      Clinical and anatomic pathology436231.343993939
      Family practice26,92231.146,5754242.3
      Internal medicine30,57330.745,9943938.7
      Radiation oncology95223.414512827.5
      Neurology262121.843063130.7
      Anesthesiology796921.510,9012625.9
      Diagnostic radiology457621.368132727.2
      Emergency medicine568120.112,6992828.3
      Ophthalmology302516.650912726.6
      Otolaryngology9111017781818.3
      Neurologic surgery2505.15329.34.2
      Orthopedic surgery6633.310955.85.8
      Female representation among RO physicians was 23.4% in 2006 and 27.5% in 2020 (4.1% increase), which was tied for the second lowest absolute growth over time among the represented specialties. Obstetrics/gynecology (14,750 [2006], 23,921 [2020]; 18.7% absolute growth) and dermatology (3568 [2006], 6329 [2020]; 15.1% absolute growth) experienced the highest absolute growth in female representation over the study period.
      When assessing changes between various time points in RO, the absolute change in female physicians increased by 1.5% between 2006 and 2011, by 2.2% between 2011 and 2016, and by only 0.4% between 2016 and 2020. The 0.4% increase between 2016 and 2020 was the lowest in comparison to the other 15 specialties (Figure 1).
      Fig 1
      Fig. 1Growth of women physicians within several medical specialties at various time points.
      Statistical analysis was undertaken on specialty characteristics (Table 2) and their association with gender diversity rank. Factors associated with a higher gender diversity rank were lower average step 1 scores (P = .0056), fewer years of training (P = .0078), fewer work hours (P = .046), the availability of a standard third year clerkship for a given specialty (P = .0061), and a high baseline number of female physicians within a specialty (P = .0078).
      Table 2Characteristics of medical specialties
      SpecialtiesGender diversity rankStep 1 averagescoreAverage number of research activitiesLength of training (years)Average weekly work hoursInterest in specialty among matriculating medical studentsDedicated 3rd year clerkshipNumber of active female physicians 2020
      Pediatrics1st2284.93479.00%Yes38,405
      Obstetrics and gynecology2nd23264586.40%Yes23,921
      Dermatology3rd24819445.42.80%No6329
      Family practice4th2213.3352.65.00%Yes46,575
      Psychiatry5th2275.6446.52.80%Yes21,827
      Pathology6th2337.34
      Data are unavailable.
      0.60%No4399
      Internal medicine7th2356.2354.913.10%Yes45,994
      Neurology8th2327.2450.82.70%Yes4306
      Emergency medicine9th2334.3346.48.60%Sometimes12,699
      Radiation oncology10th24318.3551.81.00%No1451
      Diagnostic radiology11th2416.45581.60%No6813
      Ophthalmology12th245
      Data are unavailable.
      3512.10%No5091
      Anesthesiology13th2345.24612.30%Sometimes10,901
      Otolaryngology14th24813.7553.11.30%No1778
      Neurologic surgery15th24823.4758.22.70%%No532
      Orthopedic surgery16th248145577.20%No1095
      low asterisk Data are unavailable.
      A low number of research activities (P = .099) and greater interest among matriculating medical students (P = .28) were also associated with higher gender diversity rank but were not statistically significant.

      Discussion

      This study reports on the representation of women in RO in comparison to 15 other medical specialties between 2006 and 2020 and notes minimal increase in female representation in RO over time, with the most recent years showing an unprecedented low growth pattern relative to other specialties. Significant factors predictive of increased gender representation within a specialty were a lower step 1 average, fewer years of training, fewer work hours, availability of a standard third year clerkship, and a high baseline number of female physicians within a specialty.
      Although our study evaluated predictive factors of gender diversity among all physicians (academic and nonacademic physicians), a previous study by Chapman et al
      • Chapman CH
      • Hwang W-T
      • Wang X
      • Deville C
      Factors that predict for representation of women in physician graduate medical education.
      reported predictive factors of gender diversity among specialties within academic medicine alone and also noted that a lower step 1 average, availability of a third year clerkship, and a high percentage of female faculty were predictive factors. Chapman et al, however, did not evaluate years of training and work hours as was done in the present study, but their study provides important preliminary findings that corroborate our results.
      Our predictive model for intraspecialty diversity showed that high step 1 scores and research activities were not barriers to recruiting and matching women, as evidenced by the high proportion of women in dermatology. However, our results also suggest that specialties with an overemphasis on step 1 scores are generally less gender diverse. Consequently, efforts aimed at providing a more holistic approach to residency selection
      • Odei B
      • Das P
      • Pinnix C
      • Raval R
      • Holliday EB
      Potential implications of the new USMLE step 1 pass/fail format for diversity within radiation oncology.
      will augur well for gender diversity within RO.
      We found that the inclusion of a specialty as part of the mandatory third year clerkship in medical school was predictive of increased gender diversity. The compounding realities that RO has low prematriculation interest (1%; Table 2) among medical students, limited inclusion in medical school curricula,
      • Agarwal A
      • DeNunzio NJ
      • Ahuja D
      • Hirsch AE
      Beyond the standard curriculum: A review of available opportunities for medical students to prepare for a career in radiation oncology.
      and no standard third year clerkship may provide context for why achieving higher visibility among female medical students has likely been challenging. Moreover, the little exposure to RO during the early phase of medical school is further taxed by expectations of high research productivity among residency applicants, which may dissuade some female applicants who develop a late interest in RO from pursing the specialty. Thus, efforts targeting women during the premedical and preclerkship phases will be intrinsically important to effect change. National initiatives, under the auspices of the American Society for Radiation Oncology (ASTRO) and advanced by departmental leadership, which encourage engagement of undergraduate women as they obtain shadowing and clinical experience will be a valuable area of investment and will place the recruitment pipeline “more upstream.” Furthermore, a summer research fellowship that focuses exclusively on women early in their medical education may also be an important consideration.
      Fewer years of training and fewer work hours were significant predictors of increased female representation within a specialty. The 5 years of postgraduate training in RO is longer than other specialties with a high female representation (obstetrics/gynecology [4 years], pediatrics [3 years], and dermatology [4 years]), suggesting that RO may be less attractive when considering training duration. However, the generally lower average weekly work hours in RO provides a favorable counterpoint, which may be underappreciated given the poor exposure of medical students to RO.
      Our data also showed that a high baseline number of female physicians within a specialty is an important driver of female representation within a specialty and may reflect mentorship opportunities. Given the relatively small number of the female ROs in the workforce, and the likely geographic maldistribution of mentorship opportunities, a broader coalition of willing mentors will be needed to meet the current need for early female mentorship. It will be crucial for male ROs to enthusiastically seek opportunities to mentor women in the formative years of their medical training, especially in light of recent data showing the effectiveness of cross-gender mentorships.
      • Lee A
      • Albert A
      • Griffith K
      • et al.
      Mentorship in radiation oncology: Role of gender diversity in abstract presenting and senior author dyads on subsequent high-impact publications.
      In this vein, current mentorship programs, including those sponsored by The Society for Women in Radiation Oncology,
      • Seldon C
      • Wong W
      • Jagsi R
      • Croke J
      • Lee A
      • Puckett L
      Remote mentorship in radiation oncology: Lessons to share.
      American College of Radiation Oncology,

      ACRO. ACRO mentorship program. Available at: https://www.acro.org/residents/resident-mentor-program/. Accessed May 15, 2021.

      and The Gender Equity Community,

      American Society for Radiation Oncology (ASTRO). New gender equity community opens in the ROhub. Available at: https://www.astro.org/Blog/December-2020/New-Gender-Equity-Community-opens-in-the-ROhub. Accessed May 15, 2021.

      require ongoing support and resources to achieve their important aims. Social media can also broaden the outreach of mentorship initiatives, particularly for female students at institutions without an affiliated RO department or in a scenario where only a few women mentors may be present. Ongoing efforts, such as the innovative #ILookLikeARadOnc and #WomenWhoCurie campaigns,
      • Albert AA
      • Knoll MA
      • Doke K
      • et al.
      #WomenWhoCurie: Leveraging social media to promote women in radiation oncology.
      will continue to be important in fostering inclusion and celebration of gender diversity within RO and will also be paramount in breaking down stereotypical gender barriers and perceptions.
      Although female representation in the RO workforce has been historically modest, the factors specifically influencing the recent pattern of deceleration in female growth in RO are likely complex and multifactorial and may include concerns about the trajectory of the field. In spite of this recent trend, more efforts are present than ever before aimed at tackling the issue of improving gender diversity in RO.
      • Suneja G
      • Mattes MD
      • Mailhot Vega RB
      • et al.
      Pathways for recruiting and retaining women and underrepresented minority clinicians and physician scientists into the radiation oncology workforce: A summary of the 2019 ASTRO/NCI Diversity Symposium session at the ASTRO Annual Meeting.
      In June 2017 the board of directors of ASTRO approved a new strategic plan for RO,

      American Society for Radiation Oncology (ASTRO). ASTRO strategic plan. Available at: https://www.astro.org/About-ASTRO/Strategic_Plan. Accessed April 9, 2021.

      and among the 5 core values identified were “diversity” and “inclusion.” ASTRO's Committee of Health Equity, Diversity, and Inclusion also continues to work to raise awareness and improve the representation of women in RO. These efforts are laudable and the full effect of these initiatives may take time to be fully realized.
      A limitation of our study is our use of 4 time points over time rather than reporting annual changes over time. We believe the time points functioned as strong surrogates of trends over time. Another limitation involves the use of limited specialty characteristics for our predictive model, which was likely not exhaustive of all possible factors to consider.

      Conclusions

      The proportion of women in RO continues to lag behind other medical specialties, with a worsening trend in recent years. Effective change requires a commitment to steadfast and focused interventions that address the drivers of improved diversity, which include holistic residency admission processes, initiatives to increase exposure, and expansion of mentorship opportunities. Specifically, incorporating or expanding on initiatives such as a women's summer research fellowship, improved social media utilization, and early engagement of premedical students will be important. We call on stakeholders to explore these avenues to improve female representation in RO.

      Acknowledgments

      We thank Dr Charles Thomas (OHSU) for his guidance during the course of this study.

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