The reproducibility of interventional radiology randomized controlled trials and external validation of a classification system

PURPOSE: The fragility index (FI) measures the robustness of randomized controlled trials (RCTs). It complements the P value by taking into account the number of outcome events. In this study, the authors measured the FI for major interventional radiology RCTs. METHODS: Interventional radiology RCTs published between January 2010 and December 2022 relating to trans-jugular intrahepatic portosystemic shunt, trans-arterial chemoembolization, needle biopsy, angiography, angioplasty, thrombolysis, and nephrostomy tube insertion were analyzed to measure the FI and robustness of the studies. RESULTS: A total of 34 RCTs were included. The median FI of those studies was 4.5 (range 1–68). Seven trials (20.6%) had a number of patients lost to follow-up that was higher than their FI, and 15 (44.1%) had a FI of 1–3. CONCLUSION: The median FI, and hence the reproducibility of interventional radiology RCTs, is low compared to other medical fields, with some having a FI of 1, which should be interrupted cautiously.