Table 3.
Estimated number of asymptomatic thrombophilic women or women with a positive family history for VTE who should avoid using oral contraceptives to prevent one VTE, and estimated number needed to test
OCs indicates oral contraceptives.
*Based on family studies as outlined in Table 2.
†Based on a population baseline risk of VTE in young women of 0.01% per year,16 a relative risk of VTE by use oral contraceptives of 4,17 and a relative risk of 2 of VTE by having a positive family history.14
