Comparing the effects of a patient-designed-and-informed participant information leaflet in comparison with a standard, researcher-designed information leaflet on recruitment, retention and understanding: A study-within-a-trial

BACKGROUND AND AIM: The process of trial recruitment is vital, given its impact on resources, statistical power and the validity of findings. A participant information leaflet (PIL) is often the initial and primary source of information engaged by potential participants during recruitment. Research suggests that a variety of manipulations to a PIL can be made during its development to enhance understanding, readability and accessibility. In light of this, PIL-design led by Public and Patient Involvement (PPI) may also yield positive effects in this respect, as well as consent and retention. This study-within-a-trial (SWAT) compared the effects of a PPI-developed PIL with a standard, researcher-developed PIL on rates of consent, retention, decision certainty, understanding, readability, accessibility, likeability and decision to consent. METHOD: This SWAT used a double-blind, two-armed randomised design. The SWAT was conducted within a host trial of cognitive rehabilitation in multiple sclerosis. RESULTS: A total of 234 people expressed interest in the trial, of which 94 were retained at 6-month follow up. Results revealed no effects on levels of consent and retention between the two PIL groups. CONCLUSIONS: These null effects provide interesting points of discussion and important implications for not only future research on PILs, but also for future research that involves recruitment to health-related interventions.