Funding for this research was provided by:
National Institute for Health Research (CS02016-007)
Rosetrees Trust (M627)
Received: 16 April 2020
Accepted: 18 August 2020
First Online: 16 September 2020
Ethics approval and consent to participate
: This study has Health Research Authority (HRA) approval ref: 17/HRA/3427. Ethical approval was not required since the study uses pseudonymised datasets that were collected as part of routine clinical care. The dataset is stored within the UCL Data Safe Haven accessible only by named researchers. All researchers who work on the dataset have undertaken training in information governance and GDPR within the last 12 months.
: Not applicable
: The authors declare that they have no competing interests.