What Are the Trends in Women’s Representation Among Lead Investigators of Orthopaedic Clinical Trials?
Authors: Burkhart Robert J. , Karimi Amir H. , Hecht Christian J. , Avila Amanda , Acuña Alexander J. , Kamath Atul F. 
Published: July 2023

Abstract

Background
Serving as a principal investigator for a clinical trial can bring national visibility and recognition to physicians, and it can have a substantial impact on their promotion and tenure. In the field of orthopaedics, there is a well-known gender gap in terms of representation and leadership. Examining the representation of women in clinical trial leadership may help to inform and enable the design of targeted interventions and policies to foster a more inclusive and diverse environment in clinical trial leadership.

Questions/purposes
(1) What is the proportion of women principal investigators in orthopaedic clinical trials, and has this changed over time? (2) Are there trial characteristics (trial phase, status, funding source, and intervention) associated with women principal investigators? (3) What is the geographic distribution globally and regionally within the United States of clinical trials led by women principal investigators?

Methods
A cross-sectional survey of clinical trials using the ClinialTrials.gov registry and results database provided by the NIH was performed on August 22, 2022. Trial characteristics included principal investigator names and gender, trial phase, type, funding source, intervention, and location (defined by continent and US Census region). Our primary outcome was the overall proportion of women orthopaedic principal investigators over time. We assessed this by comparing the proportion of women principal investigators from 2007 to 2022. Our secondary outcomes were trial characteristics (trial phase, status, funding source, and intervention) and geographic distribution (globally and within the United States) associated with women principal investigators. Baseline characteristics of the clinical trials were calculated using frequencies and percentages for categorical variables. Fisher exact tests were conducted to evaluate differences in gender proportions based on the included clinical trial characteristics. Univariate linear regression was applied to analyze trends in the annual proportion of women principal investigators over time.

Results
The overall proportion of women principal investigators was 18% (592 of 3246), and this proportion increased over the study period. Specifically, the proportion of women leading clinical trials was 13% (16 of 121) in 2007 and 22% (53 of 242) in 2022 (r2 = 0.68; p < 0.001). This trend was also observed when evaluating only US women principal investigators (r2 = 0.47; p = 0.003) and non-US women principal investigators over the study period (r2 = 0.298; p = 0.03). There was no difference in the distribution of trial phases between men and women principal investigators. Most men and women were involved in “not applicable” or Phase IV trials. Similarly, there was no difference in trial status or funding source. However, women principal investigators had a higher proportion of studies involving behavioral interventions (11% [67 of 592]) compared with men principal investigators (3% [74 of 2654]; p = 0.03). The proportion of women principal investigators over the study period by world region revealed a higher proportion of women principal investigators in Asia (23% [88 of 391]), followed by South America (24% [12 of 49]), North America (18% [306 of 1746]), and Europe (16% [136 of 833]). Among all US trials over the study period, the proportion of women principal investigators across the US Census region was Northeast (19% [62 of 329]), South (18% [90 of 488]), West (20% [97 of 492]), and Midwest (13% [22 of 168]).

Conclusion
Although there has been a notable increase in the proportion of women principal investigators over time, the overall representation remains relatively low. The disparities observed in trial characteristics and geographic distribution of women principal investigators further emphasize the need for targeted interventions and policies to foster a more inclusive and diverse environment in clinical trial leadership.

Clinical Relevance
These results underscore the importance of adopting practices and strategies that foster gender equity in the leadership of orthopaedic clinical trials. By establishing mentorship and sponsorship programs, early-career women surgeons can be connected with experienced leaders, cultivating a supportive network and offering valuable career guidance. Additionally, addressing geographic disparities in the representation of women principal investigators can involve the implementation of mentorship and sponsorship programs in regions with lower representation.