As follow-up participants receive a handwritten or printed post-it note either alone or with usual follow-up or a newsletter. The note contains text such as “Please take a few minutes to complete this for us. Thank you.”
Addition of a post‐it note may result in little or no difference to retention.
An increase of 0% (95% confidence interval = -1% to 1%).
GRADE Low certainty.
We recommend that trialists add post-it notes to follow-up in the context of an intervention evaluation.
See Resource bundle below for support materials.
Imagine initial retention is 65% of those approached. You have a trial with 100 participants that needs responses from 80 to meet its statistical power calculations. Retention of 65% means that you will be 15 responses short (see chart below).
Now imagine adding post-it notes to follow-up. The chart below shows the impact of an absolute increase of 0% (95% CI = -1% to 1%). Retention remains unchanged.
Trial Forge will make trials more efficient by looking for marginal gains across all trial processes, from research question to implementation into routine care. It will encourage everyone connected with trials to be more sceptical of what we do by asking for the evidence behind all of our trial decisions.