Feasibility of advanced composite endpoint analysis: Post-hoc insights from the vitamin intervention for stroke prevention randomized control trial

Abstract

Background and aimsStroke is a major cause of mortality and disability, highlighting the importance of prevention. Clinical trials play an important role in evaluating interventions that can maximize stroke prevention. Traditional composite endpoints (TCE) used in clinical trials have limitations, as they pool together events of varying clinical importance. Weighted composite endpoints (WCE) have emerged as a solution to address these limitations and provide more accurate assessments of outcomes. In this study, we investigate the use of WCE in a previously reported negative clinical trial for stroke prevention. Methods and resultsWe analyzed data from the Vitamin Intervention for Stroke Prevention (VISP) trial, which compared high dose and low dose multivitamin therapy. We utilized weighted methods to analyze time-to-event outcomes with censoring. The primary outcomes of interest were time to nonfatal stroke, nonfatal coronary events, and death. We calculated modified Kaplan-Meier (KM) curves for each intervention group. We also performed a modified log-rank test to assess significant differences based on the weighted KM curves. The analysis included 3668 VISP trial participants, and most remained event-free throughout the study period. The TCE KM curve showed no significant difference in outcomes between high dose and low dose groups. Similarly, the WCE KM curves, with different weights assigned to each outcome, did not reveal significant differences in outcomes between the studied groups. ConclusionThis post-hoc analysis confirms the negative trial results of VISP and demonstrates the feasibility of using WCE in assessing nutrition-based interventions for stroke prevention.