1. Unintended pregnancy rates differ according to combined oral contraceptive - results from the INAS-SCORE study.
- Author
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Barnett C, Dinger J, Minh TD, and Heinemann K
- Subjects
- Adolescent, Adult, Europe, Female, Humans, Nandrolone pharmacology, Pregnancy, Pregnancy, Unplanned, Proportional Hazards Models, Prospective Studies, Surveys and Questionnaires, Treatment Failure, United Kingdom, Young Adult, Contraceptive Agents, Hormonal pharmacology, Contraceptives, Oral, Combined pharmacology, Estradiol pharmacology, Estrogens pharmacology, Levonorgestrel pharmacology, Nandrolone analogs & derivatives
- Abstract
Objectives: To estimate the real-use contraceptive effectiveness of the combined oral contraceptive (COC) containing dienogest and oestradiol valerate (DNG/oEV) compared to other combined oral contraceptives (oCOC) and particularly, levonorgestrel-containing OCs (LNG). Methods: Prospective, non-interventional cohort study with two main exposure groups and one exposure subgroup: new users of DNG/oEV and oCOC, with the subgroup, LNG. In a planned secondary analysis, pregnancy outcomes were investigated, including contraceptive failure. The influence of age, parity and OC-type were assessed. Results: 30,098 COC users were followed for a total oral contraceptive exposure time of 68,362 woman-years (WY) and 287 unintended pregnancies were reported. The overall contraceptive failure rate in the European population was 0.4 events/100 WY (95% CI, 0.4-0.5). DNG/oEV showed lower contraceptive failure rates compared to the comparators. This difference was maintained when the study population was restricted to women aged 18-35 years; the pearl index (PI) for this demographic for DNG/oEV was 0.37 (95% CI 0.24-0.54) and 0.76 (95% CI 0.56-1.01) for LNG. The hazard ratios (HRs) adjusted for age, parity, smoking and BMI were 0.7 (95% CI, 0.5-0.98, p = .04) and 0.5 (95% CI, 0.3-0.8, p < .01) for DNG/oEV versus oCOC and LNG, respectively. The corresponding adjusted HRs in women aged 25 years or younger were 0.6 (95% CI 0.4-1.1) and 0.4 (95% CI, 0.2-0.8), respectively. Conclusions/discussion: DNG/oEV showed improved contraceptive effectiveness compared with oCOC and particularly LNG-COC when adjusted for age, parity, user status and smoking.
- Published
- 2019
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