Fig. 1

Overall Survival Based on Ever- (solid line) and Never-Users (dashed line) of Oral Contraceptives. In univariate analyses ever-users of oral contraceptives (n = 793) manifested a longer overall survival compared to never-users (dashed line) (n = 551) (HR = 0.73 (95 % CI: 0.62, 0.86); p = 0.0002 (accounting for left truncation). Within the cohort were a total of 562 deaths. Similar statistically significant findings were seen in univariate analyses when patients were dichotomized on the basis of duration of oral contraceptive use