MedDRA adoption and adverse event reporting quality in gastrointestinal and abdominal surgery randomised controlled trials: a cross-sectional analysis.

Abstract

The purpose of this study was to establish the frequency of Medical Dictionary for Regulatory Activities (MedDRA) utilisation in gastrointestinal and abdominal surgical trials, identify predictors of its adoption and quantify the association between MedDRA use and adverse event (AE) reporting quality as measured by Completeness scores, registry-publication Concordance and overall Transparency indices. Cross-sectional analysis of matched randomised controlled trial registry-publication pairs. 116 gastrointestinal and abdominal surgery randomised controlled trials registered on ClinicalTrials.gov with results posted between September 2009 and December 2024 and an associated peer-reviewed publication. 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. Among 116 included trials, only 22 (18.8%) explicitly documented MedDRA use. Industry-funded trials (OR=29.32, 95% CI 8.94 to 118.50, p<0.001) and those with at least one US site (OR=4.59, 95% CI 1.22 to 30.02, p=0.050) demonstrated significantly higher rates of MedDRA adoption. Trials documenting MedDRA use demonstrated significantly improved reporting across all three score parameters: Completeness score (p<0.001), Concordance score (p=0.002) and Transparency Index (p<0.001). MedDRA use was also associated with lower rates of registry-publication discordance across key safety metrics: serious AE participant count registry-publication discordance was 59.1% in MedDRA-documenting trials and 85.1% in non-MedDRA trials; mortality reporting discordance was 60.0% in MedDRA trials and 82.1% in non-MedDRA trials. Despite strong association with greater AE reporting completeness and registry-publication concordance, MedDRA adoption in gastrointestinal and abdominal surgical trials remains below 20%, concentrated among industry-funded studies. The predominance of unstandardised terminology and free-text strategies contributes to reporting inadequacies that complicate evidence synthesis and undermine evidence-based surgical practice. Journals, funding agencies, academic institutions and researchers should prioritise the adoption of standardised AE terminology to enhance transparency and improve surgical research. CRD420251081191.