Background: Safety analyses in randomized trials examine whether adverse events were caused by treatment. However, findings from safety analyses may be misleading, potentially resulting in suboptimal clinical and health decision-making. Few studies have investigated the reporting and conduct of safety analyses and a number of important questions remain unanswered.
Objectives: To assess study characteristics associated with the results (such as the quality and credibility of research results) of safety analyses.
Methods: We conducted a systematic review of 165 eligible, randomized, controlled human trials on drug safety, which we randomly selected in MEDLINE, Embase and the Cochrane Central Register of Controlled Trials (CENTRAL) until the number of them met our required sample size. Teams of two reviewers independently screened full texts of reports for eligibility, and abstract data, using standardized, pilot-tested extraction forms. We conducted univariable and multivariable logistic regression analyses to examine the association of pre-specified study characteristics (did it make an accurate definition of safety prior; did it describe the frequency clearly (i.e. times or person-times); did it accurately define denominator of adverse events) with the effect of drug safety analyses.
Progress and Discussion: Currently, we are extracting the data of these publications. Although reports of controlled trials are recorded sufficiently with regard to curative effect, they are not reported to the same level for safety. A clear understanding of safety analyses, as currently conducted and reported in published randomized controlled trials, will reveal both strengths and weaknesses of this practice. Our findings will contribute to a set of recommendations to optimize the conduct and reporting of safety analyses.