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The effects of multimedia information on recruitment and retention in a children's cardiac surgery trial.pdf (213.25 kB)

The effects of multimedia information on recruitment and retention in a children’s cardiac surgery trial: a randomised controlled SWAT (study within a trial)

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posted on 2023-05-15, 15:14 authored by Peter Knapp, Lucy Dabner, Karen Sheehan, Thirimon Moe-Byrne, Jacqueline Martin-Kerry, Rebecca Sheridan, Elizabeth Coleman, Steven Higgins


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.


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&MM;; Decision-Making Questionnaire; 3 ‘free-text’ questions (deriving subjective evaluations); trial retention. 


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.


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.


TRECA was funded by the National Institute for Health Research (NIHR) Health Services and Delivery Research Programme (NIHR HS&DR 14/21/21)

The BHF Chair of Cardiac Surgery

British Heart Foundation

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The BHF Chair of Congenital Heart Surgery

British Heart Foundation

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NIHR Bristol Biomedical Research Centre

Thermic-3 was designed and delivered in collaboration with the Bristol Trials Centre, a UKCRC registered clinical trials unit (CTU), which is in receipt of NIHR CTU support funding


Author affiliation

Department of Health Sciences, University of Leicester


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