Prior hysterectomy and oophorectomy and incident venous thrombosis risk among postmenopausal women: a population-based, case-control study.

OBJECTIVE: Hysterectomy and bilateral salpingo-oophorectomy (BSO) are associated with changes in endogenous hormone levels, yet the risk of venous thrombosis (VT) associated with hysterectomy and BSO is incompletely characterized. This study evaluated the risk of incident VT among postmenopausal women associated with combined prior hysterectomy/oophorectomy status and current use of hormone therapy (HT).
METHODS: In a case-control study, we identified incident VT cases (n = 1,623) among postmenopausal Group Health Cooperative enrollees without reproductive cancer, defining their "index date" as their VT diagnosis date (1995-2010). Matched controls had not experienced a prior VT (n = 4,480). Multiple logistic regression models estimated adjusted relative risks for VT associated with combinations of prior hysterectomy/oophorectomy status and HT use at the index date.
RESULTS: Compared with women with an intact uterus who were not using HT, there was no suggestion of greater VT risk in women with prior hysterectomy without BSO, whether they were (adjusted odds ratio [aOR] = 0.80 [95% CI: 0.57, 1.12]) or were not using HT (aOR = 1.09 [95% CI: 0.89, 1.35]). Women with prior hysterectomy and BSO who were using HT were not at a greater VT risk (OR = 1.00 [95% CI: 0.78, 1.27]), but there was evidence of a 25% greater risk associated with prior hysterectomy with BSO and no current HT use (OR = 1.25 [95% CI: 1.05, 1.49]).
CONCLUSIONS: Collectively, these and prior data do not suggest a substantial impact of hysterectomy, with or without BSO, on the risk of VT among postmenopausal women.