Thromboembolic safety of norethisterone vs levonorgestrel in combined oral contraceptive users: a pooled analysis of 4 large prospective cohort studies
Notice bibliographique
Résumé
BACKGROUND: Norethisterone (acetate) and levonorgestrel are marketed globally as components of combined oral contraceptives. Although guidelines recommend both as first-line combined oral contraceptives, no direct, comparative safety studies are available. OBJECTIVE: We directly compared the thromboembolic event risk associated with the use of norethisterone acetate-containing and levonorgestrel-containing combined oral contraceptives. STUDY DESIGN: Data regarding the cohorts of interest, norethisterone/norethisterone acetate (ethinylestradiol ≤30 µg) and levonorgestrel (ethinylestradiol ≤30 µg), were retrieved from a pooled dataset comprising 4 prospective, noninterventional, active-surveillance cohort studies in 14 European countries, the United States, and Canada, with similar study design but differing medication cohorts. Baseline characteristics and parameters of reproductive, contraceptive, and medical history were summarized using descriptive statistics. Propensity score subclassification was applied to balance baseline parameters between cohorts. Time-to-event analysis of venous thromboembolic events was performed on the basis of the extended Cox model to calculate crude and adjusted hazard ratios, including 95% confidence intervals. The time of venous thromboembolic events was censored at the end of the observation period for women who did not have an event. Women who dropped out or were lost to follow-up without reported venous thromboembolic events were censored at the time they last confirmed that they did not have an event. RESULTS: The pooled dataset included 235,437 combined oral contraceptive users who were followed up for a total of 571,163 women years. Among these, 40,142 women were users of norethisterone/norethisterone acetate (ethinylestradiol ≤30 µg), and 39,098 women were users of levonorgestrel (ethinylestradiol ≤30 µg), contributing 61,976 and 84,816 women years of observation, respectively. The observed prevalence of prognostic factors at baseline showed typical features of US and European combined oral contraceptive users. Both cohorts showed a similar, low rate of thromboembolic events, and we could exclude a 1.5-fold increased venous thromboembolism risk for norethisterone/norethisterone acetate relative to levonorgestrel (adjusted hazard ratio, 0.73; 95% confidence interval, 0.48-1.11). CONCLUSION: These data confirm the similar risk profiles of norethisterone/norethisterone acetate and levonorgestrel regarding thromboembolic events in routine combined oral contraceptive use of around 80,000 women from Europe and the United States/Canada. The analysis provides reassurance for both combined oral contraceptive users and clinicians regarding the safety of oral contraceptives and potentially opens discussion on norethisterone acetate as a potential gold standard therapy in clinical and postmarket research alongside levonorgestrel-combined oral contraceptives.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,001 | 0,002 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,002 | 0,000 |
| Bibliométrie | 0,000 | 0,002 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».