The Effect of Age, Parity and Body Mass Index on the Efficacy, Safety, Placement and User Satisfaction Associated With Two Low-Dose Levonorgestrel Intrauterine Contraceptive Systems: Subgroup Analyses of Data From a Phase III Trial
Bibliographic record
Abstract
OBJECTIVE: Two low-dose levonorgestrel intrauterine contraceptive systems (LNG-IUSs; total content 13.5 mg [average approx. 8 μg/24 hours over the first year; LNG-IUS 8] and total content 19.5 mg [average approx. 13 μg/24 hours over the first year; LNG-IUS 13]) have previously been shown to be highly effective (3-year Pearl Indices: 0.33 and 0.31, respectively), safe and well tolerated. The present subgroup analyses evaluated whether or not outcomes were affected by parity, age (18-25 vs 26-35 years), or body mass index (BMI, <30 vs ≥30 kg/m2). METHODS: Nulliparous and parous women aged 18‒35 years with regular menstrual cycles (21‒35 days) requesting contraception were randomized to 3 years of LNG-IUS 8 or LNG-IUS 13 use. RESULTS: In the LNG-IUS 8 and LNG-IUS 13 groups, 1432 and 1452 women, respectively, had a placement attempted and were included in the full analysis set; 39.2%, 39.2% and 17.1% were 18-25 years old, nulliparous and had a BMI ≥30 kg/m2, respectively. Both systems were similarly effective regardless of age, parity or BMI; the subgroup Pearl Indices had widely overlapping 95% confidence intervals. Placement of LNG-IUS 8 and LNG-IUS 13 was easier (p < 0.0001) and less painful (p < 0.0001) in women who had delivered vaginally than in women who had not. The complete/partial expulsion rate was 2.2-4.2% across all age and parity subgroups and higher in parous than in nulliparous women (p = 0.004). The incidence of pelvic inflammatory disease was 0.1-0.6% across all age and parity subgroups: nulliparous and younger women were not at higher risk than parous and older women, respectively. The ectopic pregnancy rate was 0.3-0.4% across all age and parity subgroups. Across all age and parity subgroups, the 3-year completion rate was 50.9-61.3% for LNG-IUS 8 and 57.9-61.1% for LNG-IUS 13, and was higher (p = 0.0001) among older than younger women in the LNG-IUS 8 group only. CONCLUSIONS: LNG-IUS 8 and LNG-IUS 13 were highly effective, safe and well tolerated regardless of age or parity. TRIAL REGISTRATION: Clinical trials.gov NCT00528112.
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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 | 0.007 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.003 | 0.008 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 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".