The impact of retracted randomised controlled trials on systematic reviews and clinical practice guidelines: a meta-epidemiological study

Abstract

AbstractObjectivesTo investigate whether and when the correction is done in Systematic Reviews (SRs) and Clinical Practice Guidelines (CPGs) when their included Randomised Controlled Trials (RCTs) have been retracted.DesignA meta-epidemiological study.Data sourcesThe Retraction Watch Database.Eligibility criteria for selecting studiesSRs and CPGs citing the retracted RCTs on Web of Science.Review methodsWe investigated how often the retracted RCTs were cited in SRs and CPGs. We also investigated whether and when such SRs and CPGs corrected themselves by visually inspecting their current web pages. We summarized the proportion of correction and the time from retraction to correction.ResultsWe identified 98 retracted RCTs as well as 360 articles (335 SRs and 25 CPGs) citing them. Among the 360 articles, 157 (44%) were published after the retraction, 203 (56%) were published before retraction. Among 77 articles published citing already retracted RCTs in their evidence synthesis without caution, none corrected themselves after publication. Of 203 articles published before retraction, 149 included RCTs that were later retracted in their evidence synthesis. Among them, one SR was retracted due to plagiarism. Only 5% of SRs (6/130) and 11% of CPGs (2/18) corrected their results.ConclusionsA large number of SRs and CPGs included already retracted RCTs without caution and never corrected themselves. When SRs and CPGs had included RCTs which were later retracted, only a small minority corrected their evidence syntheses. The scientific community, including publishers and researchers, should make systematic and concerted efforts to remove the impact of retracted RCTs.What is already known on this topic-Systematic Reviews (SRs) and Clinical Practice Guidelines (CPGs) aggregating randomised controlled trials (RCTs) are important sources of information for clinical decision making.-There are anecdotal reports of publications citing retracted RCTs and point to the problem of their continued citation after retraction.-However, there are no studies that comprehensively examined the fate of retracted RCTs on SRs and CPGs in their evidence synthesis.What this study adds-A considerable number of SRs and CPGs cited already retracted RCTs and none corrected themselves later.-Only a small minority of SRs (5%, 6/130) and CPGs (11%, 2/18) which cited RCTs that were later retracted corrected their findings after the retraction was announced.-The results indicate that publishers and researchers should make efforts to remove the impact of retracted RCT.