Prevalence of disability improvement as a potential outcome for multiple sclerosis trials

Background: The concept of improvement of disability recently emerged as a new target in multiple sclerosis (MS) studies since the approval of new potent drugs and for testing drugs for neuroprotection and repair. Objective: To propose a simple estimator for assessing and comparing the prevalence of improvement over time between groups. Methods: The prevalence of a transient condition takes into account the incidence and the duration of such...