Funding for this research was provided by:
Department of Health England (CHC)
Text and Data Mining valid from 2020-03-02
Received: 15 August 2019
Accepted: 27 January 2020
First Online: 2 March 2020
Ethics approval and consent to participate
: The protocol was approved by the Independent Scientific Advisory Committee for CPRD research (protocol number 16_153) and SAIL’s Information Governance Protocol Review Panel (protocol number 0693).
: Not applicable.
: The authors declare that they have no competing interests.