ArticleJAMA internal medicine2018
Association of Risk for Venous Thromboembolism With Use of Low-Dose Extended- and Continuous-Cycle Combined Oral Contraceptives: A Safety Study Using the Sentinel Distributed Database.
Article in JAMA internal medicine, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 6 papers, 1 of them a synthesis that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
6 citing papers in PubMed, 1 synthesis or guideline pooled it, 17 citations in OpenAlex.
- Distributed Cox proportional hazards regression using summary-level information.Biostatistics (Oxford, England) · 2023Pooled it
- Crossing borders securely: synthetic data and federated networks for privacy-preserving access to real-world data and emerging use cases.NPJ digital medicine · 2025Review
- Epidemiology and prevention of venous thromboembolism.Nature reviews. Cardiology · 2023Review
- Accommodating time-varying heterogeneity in risk estimation under the Cox model: a transfer learning approach.Journal of the American Statistical Association · 2023Article
- Venous thromboembolism associated with combined oral contraceptive use: a single-institution experience.Obstetrics & gynecology science · 2021Article
- Increased risk of thrombotic events in cold agglutinin disease: A 10-year retrospective analysis.Research and practice in thrombosis and haemostasis · 2020Article
Corrections and comments
- Commented on by
Authors and funding
7 authors at 4 institutions in 1 country.
Funding
Abstract
Importance: Continuous/extended cyclic estrogen use (84/7 or 365/0 days cycles) in combined oral contraceptives (COCs) could potentially expose women to an increased cumulative dose of estrogen, compared with traditional cyclic regimens (21/7 days cycle), and may increase the risk for venous thromboembolism (VTE). Objective: To determine, while holding the progestogen type constant, whether the risk for VTE is higher with use of continuous/extended COCs than with cyclic COCs among women who initiated a COC containing ethinyl estradiol and levonorgestrel. Design, Setting, and Participants: Incident user retrospective cohort study of primarily commercially insured US population identified from the Sentinel Distributed Database. Participants were women aged 18 to 50 years at the time of initiating a study COC between May 2007 and September 2015. Using a propensity score approach and Cox proportional hazards regression models, we estimated the hazard ratios of VTE overall and separately by ethinyl estradiol dose and age groups. Exposures: Initiation of continuous/extended or traditional cyclic COCs containing ethinyl estradiol or levonorgestrel of any dose. Main Outcomes and Measures: First VTE hospitalization that occurred during the study follow-up, identified by an inpatient International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis code of 415.1, 415.1x, 453, 453.x, or 453.xx. Results: We identified 210 691 initiators of continuous/extended COCs (mean [SD] age, 30.4 [8.6] years) and 522 316 initiators of cyclic COCs (mean [SD] age, 28.8 [8.3] years), with a mean of 0.7 person-years at risk among continuous/extended and cyclic users. Baseline cardiovascular and metabolic conditions (7.2% vs 4.7%), gynecological conditions (39.7% vs 32.3%), and health services utilization were slightly higher among continuous/extended cyclic than cyclic COC users. Propensity score matching decreased the hazard ratio estimates from 1.84 (95% CI, 1.53-2.21) to 1.32 (95% CI, 1.07-1.64) for continuous/extended use compared with cyclic COC use. The absolute risk difference (0.27 per 1000 persons) and the incidence rate difference (0.35 cases per 1000 person-years [1.44 vs 1.09 cases per 1000 person-years]) between the 2 propensity score-matched cohorts remained low, which may not translate into a clinically significant risk differences between cyclic and noncyclic estrogen use. Conclusions and Relevance: Holding the progestogen type constant (levonorgestrel), we observed a slightly elevated VTE risk in association with continuous/extended COC use when compared with cyclic COC use. However, due to the small absolute risk difference and potential residual confounding, our findings did not show strong evidence supporting a VTE risk difference between continuous/extended and cyclic COC use.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.