1. Tulane School of Public Health and Tropical Medicine, New Orleans, LA, USA
2. Faculty of Clinical Medicine, Hanoi University of Public Health, Hanoi, Vietnam
3. Faculty of Social and Behavioural Sciences, Hanoi University of Public Health, Hanoi, Vietnam
4. At the time of the study, Dr. Le was with Hanoi University of Public Health, Hanoi, Vietnam
5. USAID, Hanoi, Vietnam