Funding for this research was provided by:
National Institute for Health Research
Text and Data Mining valid from 2018-12-01
Received: 9 April 2018
Accepted: 19 November 2018
First Online: 6 December 2018
Ethics approval and consent to participate
: This study was approved by the LSHTM Ethics Committee. As it is a secondary analysis of publicly available data no consent was required.
: Not applicable
: The authors declare that they have no competing interests.
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