1 Center for Health Decision Science and Department of Global Health and Population, Harvard School of Public Health, Boston, MA, USA. Electronic address: nickmenzies@mail.harvard.edu.
2 Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA.
3 Department of Epidemiology, Harvard School of Public Health, Boston, MA, USA.
4 Center for Health Decision Science and Department of Global Health and Population, Harvard School of Public Health, Boston, MA, USA.