Introduction: Despite increasing awareness, women remain underrepresented in academic spine surgery. This study assessed whether women were equitably represented among spine surgeon PIs of clinical trials for degenerative spine disease research.
Methods: This was a retrospective cohort study of spine surgeon principal investigators (PIs) in the United States (2015 – 2022). Clinicatrials.gov was queried for the most common diagnoses and surgeries for degenerative spine diseases. Characteristics of spine surgeon PIs were collected from academic profiles. Participation-to-prevalence ratios (PPRs) were calculated for men and women PIs relative to their prevalence among spine surgery faculty at accredited training programs. A PPR of 0.8-1.2 indicated equitable sex representation. A PPR < 0.8 was defined as underrepresentation and >1.2 as overrepresentation.
Results: In total, 129 spine surgeon PIs of 91 clinical trials were included in this study. Overall, there were 125 male (97%) and 4 female (3%) spine surgeon PIs. Overall, women were underrepresented among spine surgeon PIs (PPR=0.64) while men had equitable representation (PPR=1.02). From 2015 to 2018, female spine surgeons were underrepresented (PPR=0.33), but achieved equitable representation from 2019 to 2022 (PPR=0.95). Male spine surgeons had consistently equitable representation across the study period (PPR range 1.00-1.03). Women had equitable representation at assistant (PPR=1.08) and associate (PPR=0.31) professor ranks, but were underrepresented at the full professor rank (PPR=0). PIs were funded by Industry (54%), Academic Institution (44%), and US Federal (2%) sources. There were no differences in funding sources by sex (P=0.36).
Conclusion : There are a limited number of female spine surgeon PIs for degenerative spine disease clinical trials, which may have negative implications on the vitality of the specialty moving forward. Future investigations are needed to understand the barriers women face in obtaining clinical trial leadership positions.