Funding for this research was provided by:
Medical Research Council (MR/N014464/1)
Received: 12 November 2020
Accepted: 14 April 2021
First Online: 7 May 2021
: All primary care data were extracted under the terms of a signed data sharing agreement with each practice and with project-specific approval following submission of a data privacy impact assessment, approved by the Caldicott Guardian, Lambeth Clinical Commissioning Group, on 12th March 2018. Separate ethical committee approval was not required (Health Research Authority, personal correspondence, 29 September 2017) since all data were fully anonymised for the purposes of research access, and all patient identifiable data had been removed.
: Not applicable.
: The authors declare that they have no competing interests.