ObjectivesTo evaluate digital, multimedia information (MMI) for its effects on trial recruitment, retention, decisions about participation and acceptability by patients, compared with printed information.DesignStudy Within A Trial using random cluster allocation within the Forearm Fracture Recovery in Children Evaluation (FORCE) study.SettingEmergency departments in 23 UK hospitals.Participants1409 children aged 4–16 years attending with a torus (buckle) fracture, and their parents/guardian. Children’s mean age was 9.2 years, 41.0% were female, 77.4% were ethnically White and 90.0% spoke English as a first language.InterventionsParticipants and their parents/guardian received trial information either via multimedia, including animated videos, talking head videos and text (revised for readability and age appropriateness when needed) on tablet computer (MMI group; n=681), or printed participant information sheet (PIS group; n=728).Outcome measuresPrimary outcome was recruitment rate to FORCE. Secondary outcomes were Decision-Making Questionnaire (nine Likert items, analysed summatively and individually), three ‘free text’ questions (deriving subjective evaluations) and trial retention.ResultsMMI produced a small, not statistically significant increase in recruitment: 475 (69.8%) participants were recruited from the MMI group; 484 (66.5%) from the PIS group (OR=1.35; 95% CI 0.76 to 2.40, p=0.31). A total of 324 (23.0%) questionnaires were returned and analysed. There was no difference in total Decision-Making Questionnaire scores: adjusted mean difference 0.05 (95% CI −1.23 to 1.32, p=0.94). The MMI group was more likely to report the information ‘very easy’ to understand (89; 57.8% vs 67; 39.4%; Z=2.60, p=0.01) and identify information that was explained well (96; 62.3% vs 71; 41.8%). Almost all FORCE recruits were retained at the 6 weeks’ timepoint and there was no difference in retention rate between the information groups: MMI (473; 99.6%); PIS (481; 99.4%).ConclusionsMMI did not increase recruitment or retention in the FORCE trial, but participants rated multimedia as easier to understand and were more likely to evaluate it positively.Trial registration numberISRCTN73136092 and ISRCTN13955395.