Received: 1 December 2020
Accepted: 23 July 2021
First Online: 16 November 2021
: Please see Methods section. The local University Ethics Committee provided ethics approval for Phases 3–5 on 24.04.2018 (REC Number: MRS-17/18-6443). Participants undertook written informed consent procedures.
: Not applicable.
: JS received royalties from the University of Warwick in relation to the Diabetes Manual programme. There are no conflicts of interest for all other authors.