Number and quality of randomized controlled trials in obstetrics published in the top general medical and obstetrics and gynecology journals.

ABSTRACT Background There has been an increasing number of randomized controlled trials (RCTs) published in obstetrics and maternal-fetal medicine to reduces biases of treatment effect and to provide insights on cause-effect of relationship between treatment and outcomes. Objectives To identify obstetrical RCTs published in top weekly general medical journals and monthly obstetrics and gynecology (OBGYN) journals, to assess their quality in reporting and to identify factors associated with publication in different journals. Methods The four weekly medical journals with the highest 2019 impact factor (New England Journal of Medicine, The Lancet, JAMA and the British Medical Journal), the top four monthly OBGYN journals with obstetrics related research (American Journal of Obstetrics and Gynecology, Ultrasound in Obstetrics and Gynecology, Obstetrics & Gynecology, The British Journal of Obstetrics and Gynaecology) as well as American Journal of Obstetrics and Gynecology MFM were searched for obstetrical RCTs in the years 2018-2020. The primary outcome was the number of obstetrical RCTs published in the OBGYN journals versus the weekly medical journals, as well as the percentage of trials published, overall and per journal. Secondary outcomes included the proportion of positive versus negative trials overall and per journal and the assessment of the study characteristics of published trials including quality assessment criteria. Results Of the 4,024 original research articles published in the 9 journals during the 3-year study period, 1,221 (30.3%) were RCTs, with 137 RCTs (11.2%) being in obstetrics (46 in 2018, 47 in 2019 and 44 studies in 2020). Thirty-three (24.1%) were published in weekly medical journals and 104 (75.9%) were published in OBGYN journals. The percentage of obstetrical RCTs published ranged from 1.5% to 9.6% per journal. Overall, 34.3% of obstetrical trials were statistically significant or ‘positive’ for the primary outcome. 24.8% of the trials were retrospectively registered after the enrollment of the first study patient. Trials published in the four weekly medical journals enrolled significantly more patients (1,801 vs 180, p Conclusion Approximately 45 trials in obstetrics and being are published every year in the highest impact journals, with one fourth being in the weekly medical journals and the remainder in the OBGYN journals. Only about a third of published obstetrical trials are positive. Trials published in weekly medical journals are larger, more likely to be funded by the government, multicenter, international, and double blinded. Quality metrics are similar between weekly medical and OBGYN journals.