Comparison of Obstetrical Randomized Controlled Trials in the United States and Abroad [ID 2683467

Abstract

INTRODUCTION: Research priorities and governing regulations differ between the United States and other nations (non-United States). This study compared the characteristics of U.S. and non-U.S. obstetric randomized controlled trials (RCTs). METHODS: Original research articles published in seven journals (NEJM, JAMA, The Lancet, AJOG, AJOG-MFM, BJOG, and Obstetrics & Gynecology) from 2017 to 2022 were examined, and all RCTs with an obstetric focus were analyzed. Studies were categorized based on whether they were conducted in the United States. RESULTS: Of 238 RCTs in this study, 110 (46.2%) occurred in the United States. Compared to non-U.S. studies, U.S. RCTs were more likely to be published in obstetrics and gynecology journals (90.9% versus 73.4%; P=.001) and to be multicenter studies (59.4% versus 29.9%; P<.001). U.S. RCTs had a smaller median sample size (172 versus 335; P<.001) and a shorter median study length (19.9 versus 28.9 months; P=.026). U.S. RCTs were less likely to study the antepartum period (P<.001), to have a primary outcome examining the fetus/neonate (11.8% versus 37.8%; P<.001), and to study preventative interventions (51.6% versus 68.9%; P=.011). There was no difference in intervention type (drug, behavior, procedure, or device; P=.96) or whether the trial had a positive result (6.0% versus 3.7%; P=.52) between U.S. and non-U.S. studies. CONCLUSION: U.S. RCTs had smaller sample sizes and shorter study lengths, perhaps because of multicenter recruitment. Despite being potentially more generalizable, U.S. studies are less likely to be published in general medical journals. Further research is warranted to pursue this discrepancy as broad dissemination of information is important for improving maternal and fetal outcomes.