[1] Los Angeles Cty Dept Publ Hlth, Nutr & Phys Act Program, Div Chron Dis & Injury Prevent, Los Angeles, CA 90010 USA
[2] Univ Calif Los Angeles, David Geffen Sch Med, Dept Family Med, Los Angeles, CA 90024 USA
[3] Univ Calif Los Angeles, Fielding Sch Publ Hlth, Dept Epidemiol, Los Angeles, CA 90095 USA
[4] Univ Calif Los Angeles, Clin & Translat Sci Inst, Populat Hlth Program, Los Angeles, CA 90095 USA