Evidence Summary
What is it?
Bespoke Participant Information Leaflet (PIL).
Does it work?
Optimising the participant information leaflet (PIL) through a particular, bespoke process involving formal user testing makes little or no difference to recruitment.
How big is the effect?
An increase of 1% (95% confidence interval = -1% to 3%).
How certain are we?
GRADE High certainty.
Recommendation
We recommend against using this intervention with the intention of increasing recruitment. Evaluation outside the UK would be useful.
How can I use this straight away?
See Resource bundle below for details of how to use bespoke Participant Information Leaflets (PIL) or build a SWAT evaluation of them into your trial.
Practical Impact
Imagine a trial that needs to recruit 30 participants and initial recruitment is 30% of those approached. This means you’d need to approach 100 people to recruit 30 of them (see chart).
Now imagine using a bespoke user-centred PIL development process. The chart below shows the impact of an absolute increase of 1% (95% CI = 1-% to 3%). Recruitment is now 31%, which means our best estimate is that 97 people would now need to be approached to recruit 30 of them.
Cumulative Meta-Analysis*

*Random effects model done using Comprehensive Meta-Analysis v3 (www.meta-analysis.com).
Differences >0% favour the intervention. The GRADE assessment is high.
Resource Bundle
How to Cite
Citation: Treweek S, Bruhn H, Gardner H. Evidence pack– Recruitment: Bespoke Participant Information Leaflet (PIL) (ID Rec5), 2021, https://www.trialforge.org/recruitment-sector/bespoke-process-pil-development/.
More Information
- This summary is from the Cochrane review of strategies to improve recruitment in randomised trials (https://doi.org/10.1002/14651858.MR000013.pub6).
- It was prepared with financial support from Evidence Synthesis Ireland.
- The ‘Does it work?’ statement is structured according to effect size and GRADE certainty as per GRADE Guidelines 26 (https://doi.org/10.1016/j.jclinepi.2019.10.014). The statement is for a trivial effect size and GRADE high certainty.
- The recommendation statement is the consensus view of the authors of this summary based on the GRADE certainty and features of the trials contributing to the evidence.
- If you have any questions contact info@trialforge.org.