SWAT 54 Protocol: Giving trial participants a thank you note or card after each study visit

Retention within clinical trials is a major problem with many trials failing to retain adequate numbers of participants. Some trial fail to retain a sufficient number of participants for their main analyses, leaving the research question for the trial unanswered. Alongside the loss of valuable healthcare and scientific knowledge, there is a loss of resources and time. Times to completion for trials can be prolonged and the costs of trials can increase. Further evidence is needed to identify the optimal strategies to retain participants in the trial.[1] Thanking participants for their involvement in a trial was reported as a strategy for trying to improve retention in a survey of Clinical Trials Units in the United Kingdom.[2] Therefore, this SWAT will investigate the effects of giving patients a thank you card after each study-related visit. It will be implemented in two unrelated trials and their results will be compared