1. Department of Epidemiology, University of California, Los Angeles Fielding School of Public Health, Los Angeles, CA, USA
2. Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, USA
3. Department of Statistics, University of California, Davis, Davis, CA, USA
4. Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
5. Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA