Combined Oral Contraceptive Adherence and Pregnancy Rates
Bibliographic record
Abstract
OBJECTIVE: To assess the relationship of adherence and pregnancy in participants using an estetrol and drospirenone combined oral contraceptive. METHODS: We performed a secondary analysis for which we pooled data from two parallel, multicenter, phase 3 trials (United States and Canada, Europe and Russia) that enrolled participants 16-50 years of age to receive estetrol 15 mg and drospirenone 3 mg in a 24 hormone and four placebo pills regimen for up to 13 cycles. Participants reported pill intake, sexual intercourse, and other contraceptive use on paper diaries. We limited this efficacy analysis to at-risk cycles (one or more reported acts of intercourse and no other contraceptive use) in participants 16-35 years of age at screening. We excluded cycles with other contraceptive use unless pregnancy occurred in that cycle. We assessed primarily the relationship between number of pills not taken per cycle and pregnancies and, secondarily, when pregnancies occurred during product use with a test for trend and χ 2 analyses as appropriate. RESULTS: Among 2,837 participants in this analysis, 31 on-treatment pregnancies occurred during 26,455 at-risk cycles. Pregnancies occurred in 0.09%, 0.25%, 0.83%, and 1.6% of cycles in which participants reported they took all hormone pills (n=25,613 cycles) or did not take one (n=405 cycles), two (n=121 cycles), and more than two (n=314 cycles) hormone-containing pills, respectively ( P <.001). No pregnancies occurred in 2,216 cycles when one or more pills were missed and missed-pill instructions were followed. All pregnancies related to not taking pills occurred in the first three cycles. Pregnancy rates ranged from 0% to 0.21% per cycle with no significant trend by cycle ( P =.45). CONCLUSION: Pregnancy occurs more frequently when combined oral contraceptive users report not taking all hormone-containing pills per 28-day cycle and exceeds 1% only when more than two pills are not taken. Pregnancies in participants who reported missed pills occurred only when missed-pill instructions were not followed. A 0.09% pregnancy risk per cycle among users of a 24 hormone and four placebo pills formulation who report taking all pills likely approximates a true method-failure rate. FUNDING SOURCE: Estetra SRL, an affiliate company of Mithra Pharmaceuticals. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov , NCT02817828 and NCT02817841.
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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 | 0.005 | 0.014 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.004 | 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".