What is it?
A series of postcards that depict the trial logo and research institute logos are mailed out. One of the postcards has a statement similar to “look out for your invitation letter in the coming weeks…” with contact details. A week later, the standard approach to recruitment with formal invitation letters is commenced.
Does it work?
Using a postcard teaser campaign made little or no difference to recruitment.
How big is the effect?
An increase of 0% (95% confidence interval = -4% to 5%).
How certain are we?
GRADE Moderate certainty.
We recommend that trialists use postcard teaser campaigns in the context of an intervention evaluation.
How can I use this straight away?
See Resource bundle below for details on how to implement a postcard teaser campaign.
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 postcard teaser campaign. The chart below shows the impact of an absolute increase of 0% (95% CI = -4% to 5%). Recruitment is still 30%, which means our best estimate is that 100 people would still need to be approached to recruit 30.
*Random effects model done using Comprehensive Meta-Analysis v4 (www.meta-analysis.com).
Differences >0% favour the intervention. The GRADE assessment is moderate because of the imprecision of a single study.
How to Cite
Citation: Treweek S, Bruhn H, Gardner H. Evidence pack– Recruitment: Postcard teaser campaign (REC23), 2023, https://www.trialforge.org/recruitment-sector/postcard-teaser-campaign-id-rec23/
- 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 trivial, small unimportant effect or no effect and GRADE Moderate 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 firstname.lastname@example.org.