Experiences of online group support for engaging and supporting participants in the National Health Service Digital Diabetes Prevention Programme: A qualitative interview study.

Programme developers should consider how to optimise online group support to help service users make behavioural changes, in terms of format, participant composition and use of health coach moderators. Further research is required to better understand who might benefit most from 'group chat' or 'discussion forum' support. Health coach moderation of online support groups is likely to facilitate engagement.