Continuation Rate of Combined Hormonal Contraception: A Prospective Multicenter Study

Abstract

Data from clinical trials regarding continuation of use and contraceptive efficacy do not always apply to the general public. Therefore, a study among typical users was conducted to assess the continuation rate at the end of 12 cycles of combined hormonal contraceptive methods, reasons for discontinuation, and the Pearl index. Prospective, observational, and multicenter study of 3443 women aged 18 to 49 years starting one of the three combined hormonal contraception methods available in Spain (the vaginal ring, the contraceptive pill, and the transdermal skin patch). The study population (intention-to-treat analysis) included 3443 women, of whom 45.4% were included in the vaginal ring group, 42.6% the pill group, and 12.1% the skin patch group. The continuation rate at 12 cycles was 45.9% for the pill, 42.3% for the vaginal ring, and 26.0% for the skin patch. The Pearl index was 0.61 (95% confidence interval [CI] 0-1.2) for the pill, 0.61 (95% CI 0-1.1) for the vaginal ring, and 2.34 (95% CI 0.3-9) for the skin patch (p<0.001). At 12 cycles, the vaginal ring and the pill showed similar continuation rates and effectiveness, which were significantly higher than the skin patch.