The effects of multimedia information on recruitment and retention in a children’s cardiac surgery trial: a randomised controlled SWAT (study within a trial) [version 1; peer review: 1 not approved]

Background: Digital multimedia information (MMI) has potential for use in trial recruitment but there is little formal evaluation. The objectives were to evaluate digital MMI about a trial for its effects on recruitment, retention, participation decisions, and patients’ acceptability, compared with printed information (PIS) alone and when combined with PIS. Methods: SWAT (study within a trial) using random parallel-group individual allocation within the Thermic-3 trial evaluating warm versus cold cardioplegia solution during cardiac surgery. Set in one UK hospital, participants were 147 children (0-16 years) awaiting surgery for congenital heart defects; 38% were female. Participants and their parents/guardian received trial information via multimedia (including text, animated videos and talking-head videos) for viewing at home (MMI group; n=49), or PIS (PIS group; n=47), or both (PIS&MMI group; n=51). Primary outcome was recruitment rate to the Thermic-3 trial comparing PIS-alone and MMI-alone. Secondary outcomes were recruitment rate comparing PIS-alone and combined PIS&MMI; Decision-Making Questionnaire; 3 ‘free-text’ questions (deriving subjective evaluations); trial retention. Results: MMI produced a 14.2% absolute increase in recruitment, which was not statistically significant: 32 (65.3%) participants were recruited from the MMI group; 24 (51.1%) from the PIS group (OR 1.80; 95% CI 0.79 to 4.10, p = 0.16); and 22 from the PIS&MMI group. There was no difference in recruitment through combined PIS&MMI (43.1% vs 51.1%; OR 0.73; 95% CI 0.33 to 1.61; p= 0.43). Questionnaires were returned by 17 (12%) participants and analysed descriptively. Trial retention (at 3 months) was high in all groups (72/77; 93.5% overall) and there was no difference due to information format received before participating. Conclusions: MMI increased recruitment to the Thermic-3 trial but the difference was not statistically significant, and the SWAT was small. Trial registration: TRECA ISRCTN73136092 and NI Hub for Trials Methodology Research SWAT Repository (SWAT 97). Thermic-3: ISRCTN13467772.