Assessing the completeness of safety reporting in clinical trials of regional anesthesia interventions: a registry-publication comparison systematic review

Background Incomplete or inconsistent reporting of adverse events (AEs) undermines the interpretability of randomized trials. In interventional regional anesthesia (RA), where procedural risks must be clearly communicated, such discrepancies may obscure safety profiles. This study evaluates concordance between AE data reported in ClinicalTrials.gov and corresponding peer-reviewed publications. Methods We conducted a systematic review of interventional RA trials registered on ClinicalTrials.gov with published results. AE data were extracted in duplicate across four domains: serious adverse events, other adverse events, treatment-related discontinuations, and all-cause mortality. Descriptive statistics characterized trial features. Bland–Altman and funnel plots assessed reporting concordance and bias. χ² tests compared reporting completeness by regulatory status. A composite 0–7 AE reporting score, derived from Food and Drug Administration Amendments Act Final Rule–mandated fields, was analyzed using linear and segmented regressions to identify predictors of reporting and temporal trends. Results Among included trials, substantial discrepancies were observed in AE counts between ClinicalTrials.gov and publications. Funnel plot asymmetry suggested possible underreporting in smaller studies. Trials subject to FDA reporting requirements were significantly more likely to report complete AE data (p<0.05). Composite AE reporting scores were higher in industry-sponsored and drug-focused trials. Segmented regression identified a modest post-Final Rule increase in reporting completeness, though recent-year instability limits interpretation. Discussion In RA trials, AE reporting is frequently incomplete or discordant across sources, with regulatory oversight linked to greater transparency. These findings highlight the need for standardized safety reporting and alignment between registries and publications to ensure accurate risk communication in anesthesiology research.