Pooled efficacy results of estetrol/drospirenone combined oral contraception phase 3 trials
Bibliographic record
Abstract
Objective To evaluate overall and subgroup efficacy of an estetrol (E4) 15 mg drospirenone (DRSP) 3 mg oral contraceptive in a 24/4-day regimen. Study design We pooled efficacy outcomes from 2 pivotal phase 3 contraceptive trials with E4/DRSP conducted in the United States/Canada and Europe/Russia. We assessed Pearl Index (PI; pregnancies per 100 participant-years) and 13-cycle life-table pregnancy rates in at-risk cycles (confirmed intercourse and no other contraceptive use) among participants 16 to 35 years. We calculated PI by age and further subcategorization (contraceptive history and body mass index [BMI]). We performed multivariable analysis using Cox regression to assess impact of potential confounding factors. Results Analyses included 3027 participants, of whom 451 (14.9%) had a BMI ≥30 kg/m 2 . The pooled PI was 1.52 (95% confidence interval 1.04 - 2.16) and the 13-cycle life-table pregnancy rate was 1.28% (0.83%–1.73%). We calculated unadjusted pooled PI in participants 16 to 25 years and 26 to 35 years of 1.61 (0.94–2.57) and 1.43 (0.78–2.40), respectively; in new starters and switchers of 1.88 (1.09–3.00) and 1.24 (0.68–2.08), respectively; and by BMI <25 kg/m 2 , 25 to 29.9 kg/m 2 , and ≥30 kg/m 2 of 1.14 (0.64–1.88), 2.19 (1.05–4.03), and 2.27 (0.83–4.94), respectively. In multivariable analysis, we found associations of prior pregnancy (hazard ratio [HR] 3.61[1.56–8.38]), Black race (HR 4.61[1.97–10.80]), age 16 to 25 years (HR 2.37[1.09–5.15]) and compliance <99% of expected pills (HR 4.21[2.04–8.66]) with conception. Conclusion E4/DRSP is an effective oral contraceptive overall and across subgroups stratified by age, contraceptive history, and BMI. Other than compliance, predictors of contraceptive failure are nonmodifiable. Implications Statement Pooled results from two phase 3 trials demonstrate high contraceptive efficacy of the novel estetrol-drospirenone oral contraceptive. Several non–modifiable risk factors, including prior pregnancy, race, and age, are associated with higher pregnancy risk. Additional research is needed to better understand predictors of combined oral contraceptive failure.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.034 | 0.046 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.008 | 0.024 |
| Bibliometrics | 0.003 | 0.002 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.003 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".