Practice variation in bilateral salpingo-oophorectomy at benign abdominal hysterectomy: a population-based study

Background — Bilateral salpingo-oophorectomy at benign hysterectomy is not recommended in premenopausal women due to its potential associations with increased all-cause mortality and cardiovascular disease, but contemporary practice patterns are unknown.

Objective — To quantify between-surgeon variation in bilateral salpingo-oophorectomy and identify surgeon and patient characteristics associated with bilateral salpingo-oophorectomy, in order to evaluate current quality of care and identify targets for knowledge translation and future research.

Study Design — We performed a population-based retrospective cross-sectional study of adult women (>20 years) undergoing benign abdominal hysterectomy from 2014 to 2018 in Ontario, Canada. Hierarchical multivariable logistic regression models, stratified by age group (<45, 45-54, >55 years), were used to model between-surgeon variation after multivariable adjustment for patient and surgeon characteristics. Cases of bilateral salpingo-oophorectomy were classified as potentially appropriate or potentially avoidable based on the presence or absence of diagnostic indications.

Results — Of 44,549 eligible women, 17,797 (39.9%) underwent concurrent bilateral salpingo-oophorectomy and 26,752 (60.1%) did not. In all three age strata, the individual surgeon providing care was one of the strongest factors influencing whether patients received bilateral salpingo-oophorectomy (median odds ratio 2.00-2.53). Surgeons accounted for over 22% of the residual observed variation in bilateral salpingo-oophorectomy in women 45-54 years, compared to 16% and 14% in women <45 and >55 years respectively. Non-gynecologic patient factors, such as obesity (OR 1.33, 95% CI 1.17-1.52, p<0.001) and residing in low income regions (OR 1.34, 95% CI 1.16-1.55, p<0.001), were also associated with bilateral salpingo-oophorectomy. Approximately 40% of patients who underwent bilateral salpingo-oophorectomy had no indication for the procedure in their discharge records.

Conclusion — Marked between-surgeon variation in bilateral salpingo-oophorectomy rates, even after adjusting for patient case mix, suggests ongoing uncertainty in practice. Stronger evidence-based guidelines on the risks and benefits of salpingo-oophorectomy as women age are needed, particularly focusing on perimenopausal women.