Funding for this research was provided by:
Department for International Development (Not applicable, Not Applicable)
Text and Data Mining valid from 2019-11-13
Received: 5 July 2019
Accepted: 22 October 2019
First Online: 13 November 2019
Ethics approval and consent to participate
: The study was approved by the London School of Hygiene Ethics Board of review. As this was secondary research, all information is available in the public domain and has been appropriately cited.
: Not applicable.
: The authors declare that they have no competing interests.