Abstract 131: Feasibility and Efficacy of Central Blinded Video Rankin Scale Outcome Assessments in a Randomized Clinical Trial

Abstract

Introduction: In randomized clinical trials, central adjudication is frequently used for study outcomes. However, stroke trials have historically used site-derived Rankin scale assessments as primary outcome. Hypothesis: A central adjudication of Rankin scale assessment is at least as accurate as site-derived assessment. Methods: We studied acute stroke survivors from the RESILIENT study, where primary outcome was the consensus Rankin scale rating of two blinded central adjudicators who independently watched video recordings of a 90-day post-stroke structured patient and/or family interview. We compared agreement rates (weighted kappa statistics) between both central adjudicators with that between the blinded site investigator and the consensus reading between central adjudicators. Results: Trial randomized 221 patients to thrombectomy or medical treatment alone. At 90 days, 161 (73%) survived and 142/161 (88%) had quality video recordings for central adjudicators. Median (interquartile range) Rankin scores were similarly 3 (2-4) for each central rater and for the site investigators. Agreement rates between central adjudicators was 79.6% (kappa=0.94, p<0.001), while agreement between site investigator and consensus rating from central adjudicators was 76.8% (kappa=0.92, p<0.001). Conclusions: Central blinded Rankin scale outcome assessment is feasible and is at least as good as site investigator assessments. For open-label trials with blinded clinical outcome assessment, central adjudication of video-recorded interviews provides safer blinding and accountability.