1. Department of Epidemiology, University of California, Los Angeles (UCLA) Fielding School of Public Health, Los Angeles, California.
2. Department of Family Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California.
3. Division of Chronic Disease and Injury Prevention, Los Angeles County Department of Public Health, Los Angeles, California.
4. Department of Community Health Sciences, University of California, Los Angeles (UCLA) Fielding School of Public Health, Los Angeles, California.