Recurrence Rates for Women with Estrogen-Associated Venous Thromboembolism

Classification of estrogen-associated venous thromboembolism (VTE) is controversial — some consider estrogen to be a provoking risk factor, whereas others consider these events to be unprovoked. This classification is important, as duration of anticoagulation is heavily influenced by context: patients with provoked events are treated with finite duration of anticoagulation, whereas those with unprovoked events may be candidates for longer-term anticoagulation. Prior studies of recurrence rates after discontinuation of anticoagulation in women with oral contraceptive–associated events have been limited by sample size, patient heterogeneity, and inconsistent results. To address this, researchers conducted a systematic review to estimate the i…