1. Department of Internal Medicine (RAM); Department of Community Health Sciences (RAM), Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada; Department of Neurology (SL, AS), Section on Statistical Planning and Analysis, UT Southwestern, Dallas, TX; Department of Biostatistics (GRC), University of Alabama in Birmingham, AB; and Mellen Center for Multiple Sclerosis (RJF), Neurological Institute, Cleveland Clinic, OH.