Funding for this research was provided by:
Bill and Melinda Gates Foundation (OPP1135522)
Received: 2 November 2017
Accepted: 20 February 2018
First Online: 6 March 2018
Ethics approval and consent to participate
: This paper works with information from Multiple Indicator Cluster Surveys and Demographic and Health Surveys, both publicly available data sources. The ethical responsibility is entirely of the institutions that conducted the surveys in each country, eliminating the requirement of this study’s ethical approval.
: Not applicable.
: The authors declare that they have no competing interests.
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