1. Centre for Health Services and Policy Research, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada
2. School of Population and Public Health, Faculty of Medicine, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada
3. Rwanda Biomedical Centre, Kigali 7162, Rwanda
4. British Columbia, Center for Disease Control, Vancouver, BC V5Z 4R4, Canada
5. Harvard Medical School, Global Health and Social Medicine, Boston, MA 02215, USA