Received: 29 October 2020
Accepted: 2 March 2021
First Online: 15 March 2021
: The THIN data collection scheme and research carried out using THIN data were approved by the NHS South-East Multicentre Research Ethic Committee in 2003. Under the terms of the approval, studies must undergo independent scientific review. Approval for this study was obtained from the THIN Scientific Review Committee in June 2020 (SRC protocol reference CitationRef removed–003-R2). Following approval, members of the research team were authorised to access the raw data for this study. All data were anonymised prior to use.The study protocol can be accessed at the European Union electronic Register of Post-Authorisation Studies (EU PAS) register (ExternalRef removed).
: Not applicable.
: The authors have no competing interests to declare. ES reports receiving funding from HDR-UK (PIONEER Hub), Wellcome, MRC, British Lung Foundation and NIHR. DP reports receiving funding from NIHR and MRC.