Background: Some studies have suggested hysterectomy procedures increase the risk of premature mortality. The aim of our study was to examine the association between hysterectomy for benign indications, with or without oophorectomy, and all-cause and cause-specific mortality.
Methods: Our cohort (666,588 women) comprised the Western Australian female population with linked hospital and health records from 1970 to 2015. We used Cox regression models to assess the association between hysterectomy and all-cause, cardiovascular disease (CVD) and cancer mortality by whether oophorectomy was performed. We included women who had hysterectomy or oophorectomy for cancer as unexposed to the benign surgery of interest, but also performed sensitivity analysis censoring follow-up at the time of surgery for cancer.
Results: Compared to no surgery, having a hysterectomy without oophorectomy prior to age 35 years was associated with an increase in all-cause (HR=1.29, 95% CI:1.19-1.40), CVD, cancer and other mortality; however from 35 years, the association became inverse. Similarly, hysterectomy with bilateral salpingo-oophorectomy (BSO) was only associated with increased all-cause mortality when undertaken prior to 45 years of age (35-44 years: HR=1.15, 95% CI:1.04-1.27). Censoring at gynaecological surgery for cancer increased the HR for hysterectomy with BSO but excluded many cancer-related deaths for women in the reference group, therefore potentially biasing the results in favour of no surgery.
Conclusions: Our study found that among women having surgery for benign conditions, hysterectomy with ovarian conservation undertaken from age 35 and hysterectomy with BSO undertaken from age 45 were not associated with poorer long-term survival.