Participants receive a text message emphasising the benefits to society of study participation along with follow-up information.
Inclusion of a societal benefit message may result in little or no difference to retention.
An increase of 0% (95% confidence interval = -4% to 4%).
GRADE Low certainty.
We recommend that trialists use a social benefit message in the context of an intervention evaluation.
See Resource bundle below for details on how to use a social benefit message.
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 using a social benefit message. The chart below shows the impact of an absolute increase of 0% (95% CI = -4% to 4%). 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.