Motivation-informed digital reminders did not increase completion of trial tasks compared to standard reminders.Completion and cost varied substantially by task complexity: diaries were almost always completed (median 100%), while image submissions were less frequently completed (median 67%) and more resource intensive. What this adds to what is knownProvides robust evidence from a randomised SWAT on reminder strategies, supporting metaanalysis and informing trial process optimisation.Highlights the importance of embedding SWATs to strengthen trial methodology. What is the implication and what should changeReminder wording may have limited impact for both simple and complex tasks.Simple tasks appear adequately supported by standard reminders, while complex tasks may require process changes or added support.Further work should clarify when motivation-informed wording adds value.
Ackermann et al. (Wed,) studied this question.