1. Departments of Pediatrics and Medical Education, Keck School of Medicine of USC, Los Angeles, CA, USA
2. Department of Epidemiology and Biostatistics, Susan and Henry Samueli College of Health Sciences, University of California, Irvine, Irvine, CA, USA
3. Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, CA, USA
4. Departments of Preventive Medicine and Dermatology, Keck School of Medicine of USC, Los Angeles, CA, USA
5. Department of Preventive Medicine, Keck School of Medicine of USC, Los Angeles, CA, USA