MedDRA Adoption and Adverse Event Reporting Quality in Gastrointestinal and Abdominal Surgery Randomized Controlled Trials: A Cross-Sectional Analysis

ABSTRACT Introduction Adverse event (AE) reporting transparency is essential for evidence-based surgical practice, yet substantial reporting gaps persist despite Consolidated Standards for Reporting Trials (CONSORT) Harms guidance. The Medical Dictionary for Regulatory Activities (MedDRA) provides standardized terminology for AE classification, but its association with AE reporting quality remains unexplored. Objectives The purpose of this study was to establish the frequency of Medical Dictionary for Regulatory Activities (MedDRA) utilization in gastrointestinal and abdominal surgical trials, identify predictors of its adoption, and quantify the association between MedDRA use and adverse event reporting quality as measured by Completeness scores, registry-publication Concordance, and overall Transparency indices. Design Cross sectional analysis of matched randomized controlled trial registry-publication pairs. Participants 116 gastrointestinal and abdominal surgery randomized controlled trials registered on ClinicalTrials.gov with results posted between September 2009 and December 2024 and an associated peer-reviewed publication. Primary and Secondary Outcome Measures Primary outcomes were differences in AE reporting quality between MedDRA-documenting and non-documenting trials, measured using Harms Reporting Completeness score (0-8), Concordance score (0-7), and Harms Transparency Index (0-15). Secondary outcomes included prevalence of MedDRA adoption and predictors of MedDRA documentation via univariable logistic regression. Results Among 116 included trials, only 22 (18.8%) explicitly documented MedDRA use. Industry-funded trials (OR=29.32, 95% CI=8.94-118.50, p