Association of oral contraceptive use with mortality: Findings from NHANES

Abstract

Background: The formulations and usage patterns of oral contraceptives have evolved, necessitating updated evidence on their long-term safety.

Objective: To assess the associations between duration of oral contraceptive use and all-cause, cardiovascular, and cancer mortality.

Methods: We analyzed 19,275 women from the National Health and Nutrition Examination Survey with mortality follow-up through 2019. Use of oral contraceptives was classified by duration (≤1, 1-5, >5 years). Weighted Cox models estimated hazard ratios with 95% CIs; restricted cubic splines examined dose-response relationships.

Results: Among 19,725 women (mean age 47.4 years), the median duration of oral contraceptive use was 3 years. Over a median follow-up of 12.2 years, compared with never-users, those using for >5 years had adjusted hazard ratios of 0.53 (95% CI, 0.37-0.76) for all-cause, 0.50 (95% CI, 0.26-0.96) for cardiovascular, and 0.38 (95% CI, 0.17-0.86) for cancer mortality, with a trend toward lower risks for all three outcomes (all P for trend <0.05). Restricted cubic splines revealed inverse linear associations with all-cause and cancer mortality, and a nonlinear association with cardiovascular mortality. Results remained consistent after propensity score matching.

Conclusions: The duration of oral contraceptive use was not associated with excess mortality risk and showed inverse linear or nonlinear associations with all-cause, cardiovascular, and cancer mortality, supporting their long-term safety.

Keywords: Cohort; Mortality; NHANES; Oral contraceptives; Women.