Gender Differences in Ophthalmic Procedural Volume: A Study of Male vs. Female Glaucoma Specialists

Purpose: To investigate whether differences in procedural volume exist between practicing male and female glaucoma specialists. Design: A cross-sectional analysis. Subjects: A total of 213 female and 666 male glaucoma specialists who performed ≥ 11 traditional, incisional glaucoma procedures for Medicare beneficiaries between 2014 and 2018. Methods: The 2014 to 2018 Medicare Provider Utilization and Payment Data database was queried using Current Procedural Terminology and Evaluation and Management codes to identify clinic visits and cataract, glaucoma drainage implant (GDI), trabeculectomy, minimally invasive glaucoma surgery (MIGS), and office-based glaucoma laser procedures. The number of procedures performed per provider was averaged and compared between genders. The univariate ordinary least squares linear regression analysis was used to investigate the effects of gender on procedural volume. The multivariate ordinary least squares linear regression analysis was used to examine the effects of gender, the number of group practice members, and the number of years after medical school graduation on cataract, GDI, trabeculectomy, MIGS, and glaucoma laser procedural volumes. Main Outcome Measures: Mean difference in the number of procedures by gender and predictors of procedural volume. Results: In the univariate analysis, men performed an estimated 7.8 more MIGSs (95% confidence interval [CI], 2.7–12.9; P = 0.003), 138.9 more cataract procedures (95% CI, 59.6–218.3; P = 0.0006), and 1.99 more GDI procedures (95% CI, 0.03–3.95; P = 0.046) than women. This relationship remained true for MIGS and cataract procedures in the multivariate analysis after controlling for clinical volume, the number of group practice members, and the number of years after medical school graduation (MIGS, β = 6.1 [95% CI, 0.5–11.8; P = 0.03]; cataract, β = 110.2 [95% CI, 16.9–203.5; P = 0.02]). Glaucoma drainage implant procedures were no longer associated with the gender of the surgeon in the multivariate analysis (β = 2.1, 95% CI, −0.1 to 4.2; P = 0.06). The volumes of trabeculectomy and office-based glaucoma laser procedures did not differ between the genders in both the univariate (glaucoma laser, β = 7.0 [95% CI, −4.4 to 18.5; P = 0.23]; trabeculectomy, β = 2.7 [95% CI, −0.8 to 6.2; P = 0.13]) and multivariate analyses (glaucoma laser, β = −7.3 [95% CI, −18.7 to 4.1; P = 0.21]; trabeculectomy, β = 1.7 [95% CI, −5.6 to 2.1; P = 0.38]). Conclusions: Women performed fewer MIGS and cataract procedures than men, even after controlling for clinical volume, the number of years after medical school graduation, and the number of group practice members. After controlling for these factors, there was no difference in the incisional glaucoma or glaucoma laser procedural volume between genders. Further research is needed to understand factors contributing to these differences.