[1] Univ Calif San Francisco, San Francisco, CA 94143 USA
[2] San Francisco VA Med Ctr, San Francisco, CA 94143 USA
[3] Northern Calif Inst Res & Educ, San Francisco, CA USA
[4] Univ Calif Davis, Davis, CA 95616 USA
[5] Columbia Univ, New York, NY 10027 USA
[6] San Francisco VA Med Ctr, 4150 Clement St,Box 111A1, San Francisco, CA 94121 USA
[7] San Francisco VA Med Ctr, 4150 Clement St,Box 111J, San Francisco, CA 94121 USA
[8] Univ Calif Davis, Dept Emergency Med, 4150 5 St,Suite 2100, Sacramento, CA 95817 USA
[9] Columbia Univ, Mailman Sch Publ Hlth, 722 West 168th St,Room 228F, New York, NY 10032 USA