Rigor, reproducibility, and transparency of randomized controlled trials in obstetrics and gynecology

Randomized controlled trials are considered the highest level of evidence but fewer than half are reproducible. A rigorous methodology improves trial quality, but reproducibility may be limited by a lack of transparency in reporting. The Consolidated Standards of Reporting Trials guidelines define reporting standards, and pretrial registration requires a predefined methodology and predefined outcomes. We evaluated obstetrics and gynecology trials published in 6 journals in terms of their adherence to the Consolidated Standards of Reporting Trials guidelines. Second, we evaluated pretrial registration compliance and concordance between the registry and publication. Furthermore, we evaluated the differences in trial characteristics among randomized controlled trials with the highest level of compliance and those with lower levels of compliance and adherence to guidelines by journal type. This was a cross-sectional study of obstetrics and gynecology trials published between 2017 and 2019 in 6 journals (American Journal of Obstetrics & Gynecology, BJOG: An International Journal of Obstetrics and Gynaecology, Obstetrics & Gynecology, The Journal of the American Medical Association, The Lancet, and The New England Journal of Medicine). Randomized controlled trials were identified via PubMed and manual journal archive searches. The primary outcome was adequate compliance with the Consolidated Standards of Reporting Trials guidelines defined as ≥80% of the checklist items present. Secondary outcomes included completion of pretrial registration and concordance between the pretrial registration and publication in terms of the outcomes and sample size. We compared the characteristics between trials with adequate compliance and those with inadequate compliance. Secondary analyses included comparisons of characteristics of the trials in the top quartile for compliance with the Consolidated Standards of Reporting Trials guidelines with those of the trials in lower quartiles and compliance with guidelines in obstetrics-gynecology vs non–obstetrics-gynecology journals. In an exploratory analysis, trends in compliance with the Consolidated Standards of Reporting Trials guidelines across the study period were assessed. A post hoc sensitivity analysis evaluated the outcomes after the exclusion of 2 retracted trials. Of the 170 trials included, 80% (95% confidence interval, 74%–86%) were adequately compliant with the Consolidated Standards of Reporting Trials manuscript guide