Funding for this research was provided by:
Bill and Melinda Gates Foundation (OPPI033910)
Received: 24 November 2016
Accepted: 28 November 2017
First Online: 8 January 2018
Ethics approval and consent to participate
: This project proposal was reviewed and approved by Independent Ethics committee of Population Council, New Delhi. Verbal consent for participation was obtained from the participants by the field interviewers before collecting the data.
: Not applicable.
: The authors declare that they have no competing interests.
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