[1] Univ Calif Los Angeles, Dept Neurol, Los Angeles, CA 90024 USA
[2] Univ Calif Los Angeles, Div Geriatr, Los Angeles, CA USA
[3] Univ Washington, Dept Neurol, Seattle, WA 98195 USA
[4] Univ Washington, Dept Epidemiol, Seattle, WA 98195 USA
[5] Univ Calif San Diego, Dept Neurol, San Diego, CA 92103 USA
[6] Univ Calif Los Angeles, Div Gen Internal Med & Hlth Serv Res, Los Angeles, CA USA