Table 1 Participant recruitment and retention strategies prior to recruitment day, at baseline, 2-weeks and 6-months

Recruitment materials written in accordance with average national literacy levels and reviewed by the trial’s Patient and Public Involvement group.

Contacted and opened a range of healthcare (GP surgeries, pharmacies) and community (local community groups, community events, one-to-one community sessions) settings for recruitment.

Venue visitors were offered time slots for participating in future recruitment day(s).

Participants were asked about their preferred time of week (weekend/weekday), time of day (morning, afternoon, evening) and method of contact (phone call, text message, e-mail, post) for their follow-ups.

Participants were encouraged to include a phone call as preferred method of contact.

Participants were informed that the trial team (based in Wales) would be calling from a number starting with the 029- telephone code.

Participants were offered a High Street shopping voucher after completing their questionnaire.

Participants were given an approximate date for their follow-ups.

Emphasis placed on the lay advisors’ affiliation with Cardiff University.