1. Maternal and Child Health Division, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka 1000, Bangladesh
2. Centre for Health Services and Policy Research, School of Population and Public Health, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada
3. School of Planning, University of Waterloo, Waterloo, ON N2L 3G1, Canada
4. Global Health and Population, Harvard T. H. Chan School of Public Health, Harvard University, 677 Huntington Ave, Boston, MA 02115, USA
5. Binary Data Lab, Dhaka 1208, Bangladesh
6. Sydney School of Public Health, The University of Sydney, Sydney, NSW 2006, Australia