Andrews JA, et al. - The experts embraced this study to examine the rate of decline in percentage predicted slow vital capacity (SVC) and its relationship with respiratory-related clinical events and mortality in patients with amyotrophic lateral sclerosis (ALS). The rate of decline in SVC was correlated with the likelihood of clinically meaningful events, such as respiratory failure or death, in these patients. Thus, implying that it was an important indicator of clinical progression.