Affiliation: | 1. Department of Pediatrics, David Geffen School of Medicine at University of California, Los Angeles, Los Angeles, California;2. Department of Internal Medicine, David Geffen School of Medicine at University of California, Los Angeles, Los Angeles, California;3. Department of Health Policy and Management, University of California, Los Angeles Fielding School of Public Health, Los Angeles, California;4. Institute for Social Research, University of Michigan, Ann Arbor, Michigan |