Menstrual Reduction With Extended Use of Combination Oral Contraceptive Pills
Bibliographic record
Abstract
In Brief OBJECTIVE To compare a traditional 28-day cycle to an extended 49-day cycle of the 30 μg ethinyl estradiol (E2)/300 μg norgestrel monophasic birth control pill regimen. METHODS Ninety subjects randomized to either 28-day cycles with 21 active pills or 49-day cycles with 42 active pills for a prospective open label trial over four 84-day reference periods or trimesters. Bleeding, pill taking, and symptom diaries were completed. The sample size with 80% power to detect a 40% reduction in bleeding days required 24 subjects in each arm. RESULTS Of the 90 women, 24 subjects (54.5%) on the 28-day cycle and 29 (63%) on the 49-day cycle completed the entire study (P = .41). There were no statistically significant differences between the two groups in demographics or continuation rates. There was a significant reduction in bleeding days in the experimental arm beginning in the first trimester (28-day = 10.9, 49-day = 6.4 mean days of bleeding, P < .001) and continuing to the fourth trimester (28-day = 11.3, 49-day = 5.8 mean days, P = .005). The number of spotting days was similar between both schedules in the first trimester (28-day = 4.8, 49-day = 3.7 mean days, P = .24) and continued into the fourth trimester (28-day = 3.4, 49-day = 2.9 mean days, P = .30). Annual expenditure for hygiene products was significantly less for extended use subjects (28-day = $41.45, 49-day = $17.54 spent, P < .001). CONCLUSION Extension of the 28-day oral contraceptive (OC) cycle to a 49-day cycle resulted in fewer bleeding days and no increase in mean spotting days or bleeding episodes. Extension of a monophasic oral contraceptive regimen from 28-day to 49-day cycles significantly decreases bleeding and hygiene product use without increased spotting.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".