1. Senior Research Advisor, Population Services International, Washington, DC, USA
2. Senior Technical Advisor, Population Services International, Washington, DC, USA. Correspondence:
3. Research Advisor, Population Services International, Washington, DC, USA
4. Research Associate, Stanford University, Stanford, CA, USA
5. Project Manager, Society for Family Health, Lusaka, Zambia
6. Research Officer, Total Family Health Organization, Accra, Ghana
7. Research, Monitoring, and Evaluation Coordinator, Total Family Health Organization, Accra, Ghana