Article History
Received: 23 September 2017
Accepted: 23 January 2018
First Online: 7 February 2018
Ethics approval and consent to participate
: Not applicable.
: Not applicable.
: Ms Porgo was an intern and Dr Beller Ferri a consultant at WHO when this study was initiated. Dr Norris is a staff member of WHO, where she is responsible for quality oversight and improvement of WHO guidelines. Dr Norris is a member of the GRADE working group. The authors declare that they have no other competing interests.
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