Contribution of unequal new patient referrals to female surgeon under-employment

Evaluating Trends in Medicare Reimbursements Between Male and Female Otolaryngologists From 2013 to 2018

OBJECTIVE

Gender-based pay disparities exist in otolaryngology. Determining whether such patterns have been consistently present could help expose whether, and to what extent, gender-based inequalities exist within our field.

STUDY DESIGN

Retrospective, cross-sectional analysis of publicly available Centers for Medicare and Medicaid Services (CMS) data for otolaryngologists from 2013 to 2018.

SETTING

A database study.

METHODS

CMS databases were used to evaluate whether gender differences exist within clinical productivity and reimbursement patterns among otolaryngologists over time, and if so, what those trends have been. Outcomes included the number of unique billing codes and charges submitted per physician (clinical productivity) and physician reimbursements. Results were controlled for geography, levels of clinical productivity, and gender.

RESULTS

Male otolaryngologists consistently submitted more charges for reimbursement (median [interquartile range, IQR], 291,539 [154,380-503,932] vs 196,029 [94,849-337,224]) and a greater number of unique billing codes (median [IQR], 52.0 [34.0-72.0] vs 41.0 [27.0-59.0]) than female otolaryngologists. Male otolaryngologists received greater reimbursements than female otolaryngologists (median [IQR], $114,390 [$61,732-$184,209] vs $72,679 [$34,855-$122,473]). Contrast ratios of estimated marginal means for reimbursements between male and female otolaryngologists demonstrated that 75% to 81% (P < .0001) of the estimated payment for physician services were received by male otolaryngologists.

CONCLUSION

There appears to be a consistent, general trend that the female gender is associated with decreased clinical productivity and lower CMS payments among otolaryngologists. These disparities persist even among highly productive female otolaryngologists. To better address gender pay disparities within otolaryngology, billing patterns among female otolaryngologists should be more closely assessed to help optimize reimbursement patterns for equivalent services provided by male otolaryngologists.

LEVEL OF EVIDENCE

Level IV.

Total knee arthroplasty reimbursement is declining overall and at a marginally faster rate amongst female orthopaedic surgeons: A Medicare analysis

Background

While the prevalence of total knee arthroplasty (TKA) is increasing, reimbursement is declining. The purpose of this study was to determine how surgeon gender influences procedure volume, reimbursement, practice style, and patient demographics for TKAs nationally and regionally between 2013 and 2021.

Methods

The Medicare Physician and Other Practitioners database was queried from 2013 to 2021 for procedure volume, TKA reimbursement, surgeon characteristics, and patient demographics for any surgeon who performed at least ten primary TKAs per year. Statistical tests were conducted to analyze differences based on surgeon gender, geography, and year.

Results

Of the 2,415,802 TKAs performed between 2013 and 2021, 1.5 % were billed by female surgeons. The number of TKAs performed annually increased by 29.1 % for female surgeons and decreased by 2.6 % for male surgeons. Between 2013 and 2021, reimbursement for TKAs decreased by 23.9 % for male surgeons and 26.2 % for female surgeons. In 2021, male surgeons were reimbursed $1017 per TKA while female surgeons were reimbursed $964 (p = 0.049). Male surgeons performed more TKAs annually in 2021 (Male: 39.3, Female: 30.9, p < 0.001), more total billable services (Male: 4148.0, Female: 2719.3, p < 0.001), and more unique billable services (Male: 70.7, Female: 55.3, p < 0.001) than female surgeons.

Conclusions

Female representation among surgeons who perform TKAs is increasing nationally. However, male surgeons treat more patients, perform more total billable services, and perform more unique billable services than female surgeons. TKA reimbursement is decreasing at a faster rate for female surgeons than male surgeons, although this is likely due to geographical differences.

Differences in primary total shoulder arthroplasty volume, reimbursement, practice styles, and patient populations based on surgeon gender: a temporal analysis

BACKGROUND

Orthopedic surgery has previously been shown to have a shortage of female physicians and a gender pay gap. However, this has not been thoroughly evaluated in the setting of shoulder surgery. The primary purpose of this study was to evaluate differences in total shoulder arthroplasty (TSA) volume, reimbursement, surgeon billing practices, and patient populations between male and female surgeons from 2013 to 2021.

METHODS

The Medicare Physician and Other Practitioners database, a publicly available dataset that includes 100% of services billed to Medicare Part B, was utilized. The database was queried for all billing episodes of Current Procedural Terminology code 23472, which encompasses both anatomic and reverse primary TSA. Procedural volume, average inflation-adjusted reimbursement per TSA, physician billing information, and the patient demographics of each surgeon who performed TSAs were collected. Welch's t-test and Kruskal-Wallis were utilized to compare male and female surgeons each year between 2013 and 2021.

RESULTS

Between 2013 and 2021, the proportion of TSAs performed by female surgeons nationally increased from 1.8% to 2.9% (+1.1%). This increase was greatest in the Northeast (2.0%-6.1%), while a decrease was seen in the Midwest (1.9%-1.6%). In 2021, there was no significant difference between male and female surgeons in the average inflation-adjusted reimbursement per TSA ($1144.00 vs. $1143.00, P = .792) and the average number of TSAs performed per surgeon (26.6 vs. 23.1, P = .105). Female TSA surgeons, on average, had less Medicare beneficiaries (348 vs. 462, P < .001), performed fewer annual services (1817 vs. 3630, P < .001), and performed fewer unique services (60 vs. 76, P < .001) compared to male surgeons. A higher proportion of female surgeon's patient populations were non-White (24% vs. 22%, P = .028), female (61% vs. 59%, P = .001), and dual enrolled Medicare-Medicaid patients (13% vs. 10%, P < .001). However, there was no difference in the average patient complexity between male and female TSA surgeons based on hierarchical condition category score (1.0783 vs. 1.0732, P = .228).

CONCLUSION

Female representation within TSA surgery is increasing nationally, with the greatest representation in the Northeast and West and the lowest representation in the South and Midwest. Although female TSA surgeons perform a similar number of TSAs, receive comparable reimbursement per TSA, and have a similarly complex patient population as their male counterparts, they perform significantly fewer total and unique billable services annually. Additionally, female TSA surgeons tend to see more non-White, women, and dual Medicare-Medicaid enrolled patients.

Led by vascular surgery, vascular interventions are increasingly performed by women

OBJECTIVE

Historically, the medical profession is a male-dominated field. Although the number of women entering surgical specialties is rising, this increase is not proportionate to the composition of medical school graduates, which are now 50% female. This study aimed to investigate the specialty and gender of practitioners performing common vascular procedures.

METHODS

Medical claims data was obtained from the Centers for Medicare and Medicaid Services. Claims were linked to provider characteristics in the National Plan and Provider Enumeration System using the national physician identifier. The study included final billing records from inpatient claims from 2017 to 2021. Procedures of interest were identified by the primary International Classification of Disease-10 Procedure Coding System codes. Provider taxonomy, gender, tenure, and region were derived from National Plan and Provider Enumeration System using their national physician identifier.

RESULTS

Among all specialties, board-certified vascular surgeons performed the highest percentage of open infrarenal aortic interventions (68.6%), endovascular aorta repairs (65.2%), carotid endarterectomies (59.1%), endovascular carotid interventions (32.4%), open arteriovenous fistulas (AVFs; 60.3%), endovascular AVFs (59.3%), open infrainguinal interventions (71.4%), and endovascular infrainguinal interventions (45.7%). For the two categories where vascular surgeons performed less than one-half of the procedures, the next most common specialties were neurology/neurosurgery (17.9%) and interventional cardiology (10.8%) for endovascular carotid interventions and interventional cardiology (11.1%) and interventional radiology (10.3%) for endovascular infrainguinal interventions. Over the 5-year period, the percentage of procedures performed by vascular surgeons increased for all categories except endovascular AVFs. Analyzing by gender, the majority of all procedures were performed by male physicians, which ranged from 88.3% (endovascular AVFs) to 94.7% (endovascular carotid intervention). Over the 5-year interval, however, all specialties had a significant increase in the percentage of vascular procedures performed by females (P < .05) except thoracic/cardiac surgery. Among all specialties, vascular surgery had the greatest absolute increase in female-performed interventions (P < .05).

CONCLUSIONS

Although the majority of vascular interventions are still performed by male practitioners, the proportion of procedures conducted by females is increasing. Among all specialties, vascular surgery has both the highest proportion and greatest absolute increase of vascular procedures performed by women. Future recruitment efforts should focus on continuing to reduce this disparity.

Does Resident Gender or Race/Ethnicity Affect Orthopaedic Surgery Case Volume During Residency Training?

Introduction

Disparities in case volumes have been reported in some surgical specialties. The objective of this study was to evaluate whether gender or racial/ethnicity disparities exist during orthopaedic surgery residency surgical case log volume.

Methods

Accreditation Council for Graduate Medical Education Case Log Database for orthopaedic surgery residents for 9 years of cohorts graduating in academic years 2013-2014 to 2021-2022 were analyzed to compare case logs between men and women, as well as race/ethnicity, defined by Association of American Medical Colleges as underrepresented in medicine (URiM) and non-URiM groups.

Results

Longitudinal analyses of total required minimum type cases indicate significant gender differences among the initial graduating cohorts with women trainees reporting 33 cases fewer than men; in the most recent years of this study period, women trainees reported 5 cases fewer than men per year. URiM trainees reported 29 cases fewer at baseline, while in the most recent years, there were no significant differences. Significant differences exist for 8 of the 15 case minimum types with fewer women cases at baseline; in the most recent years, women had fewer cases in anterior cruciate ligament Reconstruction, Ankle Fracture Fixation, Closed Reduction Forearm Fracture, Total Hip Arthroplasty, and Total Knee Arthroplasty. There were significant differences for 3 of 15 case minimum types at baseline for URiM trainees with no significant differences in most recent years. Hand was the only anatomic area with women reporting significantly more cases than men, both initially and over the 9 years of study period.

Conclusion

Significant differences exist in case volume and case types during orthopaedic surgery residency based on gender for the initial cohort, albeit lessening in most recent years. Although initial differences in cases volumes based on race/ethnicity exist, no significant differences persist in most recent years of the study period.

Level of Evidence

Level III. See Instructions for Authors for a complete description of levels of evidence.

Gender Differences in the Pediatric Neurosurgical Workforce: Professional Practice, Work-Life Balance, and Beyond

BACKGROUND AND OBJECTIVES

Evidence suggests that female neurosurgeons experience unique challenges in the workplace including lack of academic advancement, challenges with work-life balance, harassment, and discrimination. How these factors influence the gender gap in neurosurgery remains unclear. This analysis investigated gender differences in pediatric neurosurgeons in professional and nonprofessional activities and responsibilities.

METHODS

A survey examining professional activities, work-life balance, family dynamics, career satisfaction, and workplace discrimination and harassment was administered to 495 pediatric neurosurgeons. Response rate was 49% (n = 241).

RESULTS

One-third of the pediatric neurosurgical workforce is female. There were no gender differences in race/ethnicity, American Board of Neurological Surgery/American Board of Pediatric Neurological Surgery certification rates, or pediatric neurosurgery fellowship completion. No gender differences were found in operative caseload, weekly hours worked, or working after 8 pm or weekends. Women took call more frequently than men ( P = .044). Men were more likely to work in academia ( P = .004) and have salary subsidization from external sources ( P = .026). Women were more likely to anticipate retirement by age 65 years ( P = .044), were less happy with call commitments ( P = .012), and worked more hours at home while off ( P = .050). Women more frequently reported witnessing and experiencing racial discrimination ( P = .008; P < .001), sexual harassment ( P = .002, P < .001), and feeling less safe at work ( P < .001). Men were more likely married ( P = .042) with 1 ( P = .004) or more children ( P = .034). Women reported significantly greater responsibility for child and domestic care ( P < .001). There were no gender differences in work-life balance, feeling supported at work, or having enough time to do things outside of work.

CONCLUSION

Despite little difference in workload and professional responsibilities, women held more domestic responsibilities and experienced and witnessed more racial and sexual discrimination in the workplace. Surprisingly, there were no reported differences in work-life balance or feeling supported at work between genders. These findings suggest that factors unique to female neurosurgeons may contribute to continued gender disparity in the field.

"Women's work": Gender and the physician workforce

Historically, the physician professional identity and the organizational structure of Western medicine have been defined by masculine norms such as authority and assertiveness. The past five decades have seen a rapid shift in the demographics of attendees as medical schools, with equal numbers of women and men matriculants for nearly twenty years. Gender as a social, cultural, and structural variable continues to influence the physician workforce. The entry of women into medicine, has had far reaching effects on the expectations of patients, the interactions of physicians with other members of the healthcare team, and the delivery of care. Redefining the culture of medicine to accommodate the diversity of the modern workforce may benefit all physician and improve the delivery of healthcare.

Barriers and Facilitators to Clinical Practice Development in Men and Women Surgeons

Importance

Many early-career surgeons struggle to develop their clinical practices, leading to high rates of burnout and attrition. Furthermore, women in surgery receive fewer, less complex, and less remunerative referrals compared with men. An enhanced understanding of the social and structural barriers to optimal growth and equity in clinical practice development is fundamental to guiding interventions to support academic surgeons.

Objective

To identify the barriers and facilitators to clinical practice development with attention to differences related to surgeon gender.

Design, Setting, and Participants

A multi-institutional qualitative descriptive study was performed using semistructured interviews analyzed with a grounded theory approach. Interviews were conducted at 5 academic medical centers in the US between July 12, 2022, and January 31, 2023. Surgeons with at least 1 year of independent practice experience were selected using purposeful sampling to obtain a representative sample by gender, specialty, academic rank, and years of experience.

Main Outcomes and Measures

Surgeon perspectives on external barriers and facilitators of clinical practice development and strategies to support practice development for new academic surgeons.

Results

A total of 45 surgeons were interviewed (23 women [51%], 18 with ≤5 years of experience [40%], and 20 with ≥10 years of experience [44%]). Surgeons reported barriers and facilitators related to their colleagues, department, institution, and environment. Dominant themes for both genders were related to competition, case distribution among partners, resource allocation, and geographic market saturation. Women surgeons reported additional challenges related to gender-based discrimination (exclusion, questioning of expertise, role misidentification, salary disparities, and unequal resource allocation) and additional demands (related to appearance, self-advocacy, and nonoperative patient care). Gender concordance with patients and referring physicians was a facilitator of practice development for women. Surgeons suggested several strategies for their colleagues, department, and institution to improve practice development by amplifying facilitators and promoting objectivity and transparency in resource allocation and referrals.

Conclusions and Relevance

The findings of this qualitative study suggest that a surgeon's external context has a substantial influence on their practice development. Academic institutions and departments of surgery may consider the influence of their structures and policies on early career surgeons to accelerate practice development and workplace equity.

Defining the Disparity: A Multi-Institutional Analysis of Factors Associated With Decreased Resident Operative Experience

INTRODUCTION

Technical learning in surgical training is multifaceted and existing literature suggests a positive relationship between case volume and proficiency. Little is known about factors associated with a decreased volume of operative experience. This study aimed to identify resident and program factors associated with general surgery residents (GSR) in the bottom quartile of logged case volume upon program completion.

METHODS

A post hoc analysis of a multicenter study was used to examine case logs for categorical GSR. Participants included graduates between 2010 and 2020 from 20 programs. Residents below and above the 25th percentile for total operative volume were compared.

RESULTS

The present study includes 1343 GSR who graduated over the 11-y period. In total, 336 residents were below the 25th percentile and 1007 residents were above the 25th percentile. Those below the 25th percentile were more likely to be female (41% versus 34%, P = 0.02), identify as underrepresented in medicine (22% versus 14%, P < 0.01), and pursue fellowship (86% versus 80%, P = 0.01) compared to those above the 25th percentile. Residents below the 25th percentile were more likely to have graduated from a low volume program (55% versus 25%, P < 0.01) and from top National Institutes of Health funded institutions (57% versus 52%, P = 0.01).

CONCLUSIONS

This study identified individual and program characteristics associated with lower operative volume of GSR. Understanding such characteristics will aid surgical educators to achieve better equity in training.

Referring and Specialist Physician Gender and Specialist Billing

Importance

While a gender pay gap in medicine has been well documented, relatively little research has addressed mechanisms that mediate gender differences in referral income for specialists.

Objective

To examine gender-based disparities in medical and surgical specialist referrals in Ontario, Canada.

Design, Setting, and Participants

This cross-sectional study included referrals for specialist care ascertained from Ontario Health Insurance Plan physician billings for fiscal year 2018 to 2019. Participants were specialist physicians who received new patient consultations from April 1, 2018, to March 31, 2019, and the associated referring physicians. Data were analyzed from April 2018 to March 2020, including a 12-month follow-up period.

Exposures

Specialist and referring physician gender (female or male).

Main Outcomes and Measures

Revenue per referral was defined based on an episode-of-care approach as total billings for a 12-month period from the initial consultation. Mean total billings for female and male specialists were compared and the differential divided into the portion owing to referral volume vs referral revenue. Difference-in-differences multivariable regression analysis was used to estimate gender-based differences in revenue per referral. For each referring physician, gender-based differences in referral patterns were examined using case-control analysis, in which specialists who received a referral were compared with matched control specialists who did not receive a referral. This analysis considered the gender of the specialist and concordance between the gender of the referring physician and specialist, among other characteristics.

Results

Of 7 621 365 new referrals, 32 824 referring physicians, of whom 13 512 (41.2%) were female (mean [SD] age, 46.3 [11.6] years) and 19 312 (58.8%) were male (mean [SD] age, 52.9 [13.5] years), made referrals to 13 582 specialists, of whom 4890 (36.0%) were female (mean [SD] age, 45.6 [11.0] years) and 8692 (64.0%) were male (mean [SD] age, 51.8 [13.0] years). Male specialists received more mean (SD) referrals than did female specialists (633 [666] vs 433 [515]), and the mean (SD) revenue per referral was higher for males ($350 [$474]) compared with females ($316 [$393]). Adjusted analysis demonstrated a -4.7% (95% CI, -4.9% to -4.5%) difference in the revenue per referral between male and female specialists. Multivariable regression analysis found that physicians referred more often to specialists of the same gender (odds ratio, 1.04; 95% CI, 1.03-1.04) but had higher odds of referring to male specialists (odds ratio, 1.10; 95% CI, 1.09-1.11).

Conclusions and Relevance

In this cross-sectional study of the gender pay gap in specialist referral income, the number and revenue from referrals received differed by gender, as did the odds of receiving a referral from a physician of the same gender. Future research should examine the effectiveness of different policies to address this gap, such as a centralized, gender-blinded referral system.

Workforce Attrition Among Male and Female Physicians Working in US Academic Hospitals, 2014-2019

Importance

Retaining female physicians in the academic health care workforce is necessary to serve the needs of sociodemographically diverse patient populations.

Objective

To investigate differences in rates of leaving academia between male and female physicians.

Design, Setting, and Participants

This cohort study used Care Compare data from the Centers for Medicare & Medicaid Services for all physicians who billed Medicare from teaching hospitals from March 2014 to December 2019, excluding physicians who retired during the study period. Data were analyzed from November 11, 2021, to May 24, 2022.

Exposure

Physician gender.

Main Outcome and Measures

The primary outcome was leaving academia, which was defined as not billing Medicare from a teaching hospital for more than 1 year. Multivariable logistic regression was conducted adjusting for physician characteristics and region of the country.

Results

There were 294 963 physicians analyzed (69.5% male). The overall attrition rate from academia was 34.2% after 5 years (38.3% for female physicians and 32.4% for male physicians). Female physicians had higher attrition rates than their male counterparts across every career stage (time since medical school graduation: <15 years, 40.5% vs 34.8%; 15-29 years, 36.4% vs 30.3%; ≥30 years, 38.5% vs 33.3%). On adjusted analysis, female physicians were more likely to leave academia than were their male counterparts (odds ratio, 1.25; 95% CI, 1.23-1.28).

Conclusions and Relevance

In this cohort study, female physicians were more likely to leave academia than were male physicians at all career stages. The findings suggest that diversity, equity, and inclusion efforts should address attrition issues in addition to recruiting more female physicians into academic medicine.

Disparities in the Operative Experience Between Female and Male General Surgery Residents: A Multi-institutional Study From the US ROPE Consortium

OBJECTIVE

To examine differences in resident operative experience between male and female general surgery residents.

BACKGROUND

Despite increasing female representation in surgery, sex and gender disparities in residency experience continue to exist. The operative volume of male and female general surgery residents has not been compared on a multi-institutional level.

METHODS

Demographic characteristics and case logs were obtained for categorical general surgery graduates between 2010 and 2020 from the US Resident OPerative Experience Consortium database. Univariable, multivariable, and linear regression analyses were performed to compare differences in operative experience between male and female residents.

RESULTS

There were 1343 graduates from 20 Accreditation Council for Graduate Medical Education-accredited programs, and 476 (35%) were females. There were no differences in age, race/ethnicity, or proportion pursuing fellowship between groups. Female graduates were less likely to be high-volume residents (27% vs 36%, P < 0.01). On univariable analysis, female graduates performed fewer total cases than male graduates (1140 vs 1177, P < 0.01), largely due to a diminished surgeon junior experience (829 vs 863, P < 0.01). On adjusted multivariable analysis, female sex was negatively associated with being a high-volume resident (OR = 0.74, 95% CI: 0.56 to 0.98, P = 0.03). Over the 11-year study period, the annual total number of cases increased significantly for both groups, but female graduates (+16 cases/year) outpaced male graduates (+13 cases/year, P = 0.02).

CONCLUSIONS

Female general surgery graduates performed significantly fewer cases than male graduates. Reassuringly, this gap in operative experience may be narrowing. Further interventions are warranted to promote equitable training opportunities that support and engage female residents.

Gender Homophily in Interphysician Referrals to Surgeons

INTRODUCTION

The literature on gender homophily has mostly been focused on patient-physician relationship but not on interprofessional referrals. The goal of this study is to quantify interphysician gender homophily of referring physicians in surgical referrals.

METHODS

An observational study of the referral data at a large academic center was performed. Patients referred through Epic to the department of general surgery from January 2016 to October 2019 were included. The primary end point was gender homophily and the primary independent variable was referring physician gender. Gender homophily was defined as greater than expected rates of gender concordance. Gender concordance was defined when referring physicians have the same gender as receiving surgeons. The expected concordance rate was defined as the availability of gender-concordant surgeons in the population. Absolute homophily is the difference between observed and expected concordance rates, whereas relative homophily is the ratio between observed and expected concordance rates.

RESULTS

A total of 25,271 patient referrals from 2625 referring physicians to 91 surgeons were analyzed. The overall observed concordance rate for the entire study population was 55.3% and was 31.7% among female physicians and 82.4% among male physicians. Compared to the expected concordance rate, the absolute gender homophily among all female physicians was +7.2% or a relative homophily of 1.29%. In contrast, the absolute gender homophily among all male physicians was +6.9% or a relative homophily of 1.09%.

CONCLUSIONS

Gender homophily exists in interprofessional referrals. Although referral decisions are presumably based solely on clinical factors, referrals can be affected by subjective biases.

The surgical gender gap: the impact of surgeon gender in medicine and gynecologic surgery

PURPOSE OF REVIEW

The purpose of this review is to summarize the current literature evaluating the effect of surgeon gender on patient outcomes and satisfaction, and the impact of gender bias on female surgeons.

RECENT FINDINGS

The proportion of female physicians has increased in recent years, especially in Obstetrics and Gynecology. Recent literature assessing this impact supports equivalent or superior medical and surgical outcomes for women surgeons and physicians. It also reveals superior counseling and communication styles as perceived by patients. However, women in medicine receive lower patient ratings in competence, medical knowledge, and technical skills despite the existing evidence. Additionally, female physicians experience pay inequality, limited advancement opportunities, higher prevalence of microaggressions, and higher rates of burnout.

SUMMARY

Recognition of gender bias is essential to correcting this issue and improving the negative impact it has on female physicians, our patients, and the field of women's health.

Sex Differences in the Pattern of Patient Referrals to Male and Female Surgeons

Importance

Studies have found that female surgeons have fewer opportunities to perform highly remunerated operations, a circumstance that contributes to the sex-based pay gap in surgery. Procedures performed by surgeons are, in part, determined by the referrals they receive. In the US and Canada, most practicing physicians who provide referrals are men. Whether there are sex-based differences in surgical referrals is unknown.

Objective

To examine whether physicians' referrals to surgeons are influenced by the sex of the referring physician and/or surgeon.

Design, Setting, and Participants

This cross-sectional, population-based study used administrative databases to identify outpatient referrals to surgeons in Ontario, Canada, from January 1, 1997, to December 31, 2016, with follow-up to December 31, 2018. Data analysis was performed from April 7, 2019, to May 14, 2021.

Exposures

Referring physician sex.

Main Outcomes and Measures

This study compared the proportion of referrals (overall and those referrals that led to surgery) made by male and female physicians to male and female surgeons to assess associations between surgeon, referring physician, or patient characteristics and referral decisions. Discrete choice modeling was used to examine the extent to which sex differences in referrals were associated with physicians' preferences for same-sex surgeons.

Results

A total of 39 710 784 referrals were made by 44 893 physicians (27 792 [61.9%] male) to 5660 surgeons (4389 [77.5%] male). Female patients made up a greater proportion of referrals to female surgeons than to male surgeons (76.8% vs 55.3%, P < .001). Male surgeons accounted for 77.5% of all surgeons but received 87.1% of referrals from male physicians and 79.3% of referrals from female physicians. Female surgeons less commonly received procedural referrals than male surgeons (25.4% vs 33.0%, P < .001). After adjusting for patient and referring physician characteristics, male physicians referred a greater proportion of patients to male surgeons than did female physicians; differences were greatest among referrals from other surgeons (rate ratio, 1.14; 95% CI, 1.13-1.16). Female physicians had a 1.6% (95% CI, 1.4%-1.9%) greater odds of same-sex referrals, whereas male physicians had a 32.0% (95% CI, 31.8%-32.2%) greater odds of same-sex referrals; differences did not attenuate over time.

Conclusions and Relevance

In this cross-sectional, population-based study, male physicians appeared to have referral preferences for male surgeons; this disparity is not narrowing over time or as more women enter surgery. Such preferences lead to lower volumes of and fewer operative referrals to female surgeons and are associated with sex-based inequities in medicine.