1. From the Division of Epidemiology and Community Health (K.L., C.S., D.R.J., R.V.L.), School of Public Health, University of Minnesota, Minneapolis, MN; Department of Neurology (K.L., D.C.A., G.V., M.E.), Medical School, University of Minnesota, Minneapolis, MN; Division of Health Services Research and Policy (B.V.), School of Public Health, University of Minnesota, Minneapolis, MN.