1. Department of Epidemiology and Biostatistics, Arnold School of Public Health, University of South Carolina, Columbia, SC 29028, USA
2. Department of Epidemiology and Biostatistics, College of Human Medicine, Michigan State University, East Lansing, MI 48824, USA
3. Centre for International Public Health and Environmental Research, Bangladesh (CIPHER,B), Dhaka 1207, Bangladesh
4. Johns Hopkins Bloomberg School of Public Health, 615 N Wolfe St., Baltimore, MD 21205, USA
5. Department of Biomedical Engineering, Institute for Quantitative Health Science and Engineering (IQ), Michigan State University, East Lansing, MI 48824, USA
6. Research Unit of Medical Imaging, Physics and Technology, Faculty of Medicine, University of Oulu, 90220 Oulu, Finland
7. Department of Health Policy and Management, College of Public Health, University of Georgia, Athens, GA 30602, USA