1. Program in Public Health, Susan and Henry Samueli College of Health Sciences, University of California, Irvine, Irvine, California, USA
2. Department of Statistics, Donald Bren School of Information and Computer Sciences, University of California, Irvine, Irvine, California, USA
3. Department of Epidemiology, School of Medicine, Susan and Henry Samueli College of Health Sciences, University of California, Irvine, Irvine, California, USA