How Fragile Are Clinical Trial Outcomes That Support the CHEST Clinical Practice Guidelines for VTE?

Background: VTE remains a health concern for global populations. Clinical practice guidelines are necessary to guide physicians in the prophylaxis and treatment of VTE. Methods: Our investigation assessed the robustness of the underlying evidence in 21 randomized controlled trials (RCTs) used to support treatment recommendations in the 2016 update of the CHEST Guideline and Expert Panel Report on Antithrombotic Therapy for VTE Disease. We calculated the fragility index and fragility quotient for qualifying outcomes within RCTs. Results: The median fragility index for all studies was 5 (interquartile range, 1-9), with a median fragility quotient of 0.012 (interquartile range, 0.002-0.032). Conclusions: Our conclusions parallel those of previous investigations of the fragility of RCT outcomes; we found that some outcomes used to support recommendations in AT10 are fragile. We recommend that the fragility index and fragility quotient be adopted as measures of robustness of clinical trial outcomes.