1. Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Socinstrasse 57, Basel, Switzerland
2. University of Basel, Petersplatz 1, Basel, Switzerland
3. Department of Health Systems, Impact Evaluation and Policy, Ifakara Health Institute, Plot 463, Kiko Avenue Mikocheni, Dar es Salaam, Tanzania, and
4. Novartis Foundation, Basel, Switzerland