Published on in Vol 9, No 12 (2021): December
Preprints (earlier versions) of this paper are
available at
https://preprints.jmir.org/preprint/29098, first published
.

1 School of Health Sciences, University of East Anglia , Norwich , GB
2 Department of Behavioural Science and Health, University College London , London , GB
3 Norwich Medical School, University of East Anglia , Norwich , GB
4 Behavioural Insights, Public Health England , London , GB
5 SPECTRUM Consortium , London , GB