[1] San Francisco VA Med Ctr, San Francisco, CA USA
[2] Univ Calif San Francisco, Dept Epidemiol & Biostat, 550 16th St, San Francisco, CA 94143 USA
[3] Univ Calif San Francisco, Inst Global Hlth Sci, San Francisco, CA 94143 USA
[4] Univ Calif San Francisco, FI Proctor Fdn, San Francisco, CA 94143 USA
[5] Ctr Hlth Informat & Commun, US Dept Vet Affairs Hlth Serv & Dev, Indianapolis, IN USA
[6] Richard L Roudebush VA Med Ctr, Dept Med, Indianapolis, IN USA
[7] Vet Affairs Med Ctr, Indianapolis, IN USA
[8] Indiana Univ Sch Med, Dept Med, Indianapolis, IN 46202 USA
[9] Regenstrief Inst Hlth Care, Indianapolis, IN USA
[10] Univ Calif San Francisco, Dept Med, San Francisco, CA 94143 USA