iQuEST: Investigating the Quality and Epidemiology of Surgical Trials

Abstract

Randomised controlled trials (RCTs) provide clinicians with the best evidence for interventions, but are subject to systematic errors (bias) when methodology is not optimal. These biases occur at any time from the inception, execution, data collection, analysis, and dissemination of results. Performing RCTs for surgical interventions is additionally challenging, given the relative complexities of surgical interventions and patients, and the culture of surgical training. This thesis examined the epidemiology and quality characteristics of RCTs of surgical interventions. A systematic search was conducted to locate recently published surgical RCTs and meta-analyses, in order to attain a sample that would be reflective of the current state of surgical evidence. Data was piloted and collected according to a proforma. The first study assessed the epidemiology and methodological quality of surgical RCTs, and compared these characteristics with what is known about general medical RCTs. The second study assessed reporting quality by compliance with the Consolidated Standards of Reporting Trials (CONSORT) statement. The third study investigated the association between methodological quality and treatment effects in surgical RCTs. The fourth and fifth studies examined patterns of outcome reporting. The association between statistical significance and reporting of outcomes (outcome reporting bias) was explored. The extent to which outcomes measured in surgical RCTs are patient important was also assessed. Finally, the sixth study assessed the epidemiology, reporting and methodological quality of meta-analyses of surgical RCTs. The results show that there is substantial room for improvement in the conduct and reporting of RCTs of surgical interventions. Inadequate methodology was common, and was associated with an exaggeration of treatment effects. There was concerning evidence of unreported outcomes, and complete outcome reporting was associated with statistical significance. Only two thirds of primary outcomes were patient important. If the truth about surgical interventions is to be discerned, the conduct and reporting of surgical trials must improve. Much of this responsibility lies with study authors, but journal editors and reviewers, and the funders of research also have an important role. Existing guidelines need to be promoted and imposed, and existing multicentre models for the conduct of surgical trials should be further explored.