# A randomised Study Within a Trial (SWAT) to determine if participant information leaflet design affects recruitment rate into an interventional trial taking place in a UK emergency department

## TL;DR

This study tested if changing the design of participant information leaflets affects recruitment rates in a UK emergency department trial, but found no significant difference.

## Contribution

The study provides empirical evidence that PIL design changes do not significantly influence recruitment rates or decision-making in emergency trial settings.

## Key findings

- Optimized PILs had a 47.1% recruitment rate compared to 48.9% for conventional PILs, with no statistical significance.
- No significant differences were found in participants' decision-making based on PIL type.
- Readability and visual improvements in PILs did not impact recruitment or decision-making.

## Abstract

Exploring barriers and enablers to participant recruitment into trials is a common discussion point in trial methodology. Participant information leaflets (PIL) can be long, have complexity above the average UK reading age, and may discourage engagement with research.

This Study Within a Trial (SWAT) explored whether changing the design of a PIL influences recruitment rate and its value in patient decision-making. It was conducted within a host trial taking place in an emergency setting, where time is at a premium, and decisions on trial participation are needed more quickly than in most non-emergency settings.

We have conducted a randomised SWAT, comparing the standard format PIL with one that has been adapted to be visually appealing, with improved readability and reduced word count. Patients considered eligible for the host trial were provided with a randomly allocated PIL type; consent rates were compared. Those consenting to take part in the host trial were asked to complete a questionnaire to explore the value of the PIL in their decision-making to take part in the trial; responses were compared across the two information sheets. The sample size was dictated by host trial recruitment.

Between September 2019 and September 2022, with a brief pause during the COVID19 pandemic, 271 participants were randomised to receive either the optimised PIL (n = 138) or the conventional PIL (n = 133). The recruitment rates were 47.1% (65/138) in the optimised PIL group and 48.9% (65/133) in the conventional PIL group; this difference was not statistically significant (p = 0.771). There were no significant differences in responses from participants recruited to the host trial who completed the Decision-Making Questionnaire.

Improving the readability and visual presentation of the participant information sheet provided to participants had no effect on recruitment rate, and did not appear to impact decision-making of recruited participants.

The online version contains supplementary material available at 10.1186/s13063-025-09412-6.