Relative effects of forced vital capacity and <scp>ALSFRS‐R</scp> on survival in <scp>ALS</scp>

INTRODUCTION/AIM Amyotrophic lateral sclerosis (ALS) is a degenerative neuromuscular disease with marked clinical heterogeneity. This heterogeneity can be partly captured by clinical measures, such as the forced vital capacity (FVC) and ALS Functional Rating Scale-Revised (ALSFRS-R). We aimed to further characterize the performance of these clinical measures, including their independence and additivity, in predicting mortality. METHODS We leveraged the Pooled Resource Open-Access ALS Clinical Trials (PRO-ACT ALS) database, which includes data from 23 clinical trials (n = 2050). The primary exposures were baseline FVC and ALSFRS-R. The primary outcome was 1-y mortality. We performed correlation analyses, survival analyses and assessed classification performance using receiver operator characteristic (ROC) curves. RESULTS FVC and ALSFRS-R were weakly correlated (r = 0.31, p