1. Berkeley Population Center, University of California, Berkeley, CA, USA
2. Department of Health Promotion, Education, and Behavior, University of South Carolina, Columbia, SC, USA
3. Department of Epidemiology, University of Michigan, Ann Arbor, MI, USA
4. Department of Epidemiology and Biostatistics, University of South Carolina, Columbia, SC, USA
5. School of Kinesiology, Queen’s University, Ontario, Canada