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Top 5 Recruitment Tips


Opt-out, rather than opt-in, procedures may improve recruitment where it can be done. There’s only one evaluation so replication studies would be useful.


Having an open, rather than a blinded trial improves recruitment. The downside is that lack of blinding brings its own problems with outcome assessment


Telephone reminders to non-responders. Decent evidence but in trials with very low initial recruitment. Replication studies would help.


Enclosing a questionnaire covering issues relevant to the trial together with the invitation. Only one evaluation so replication would be useful.


Financial incentives. Odds-on that this is effective but some inconsistency in effect. Replication needed.

More About Recruitment

Trials across the world struggle to recruit sufficient participants in the timescale originally defined for recruitment activity. This can result in recruitment time extensions and/or extensions to the trial budget; it is important to note that an extension denoted strictly to time is not necessarily a ‘free’ extension and may result in opportunity lost costs for the trial team and units involved. Trial extensions may delay the availability of beneficial interventions to the public, or could result in harmful or useless interventions being used for longer time periods than is ethically necessary.

In the worst cases trials can be abandoned as a result of poor recruitment, costing large amounts of money and leaving the research question unanswered.

Trial Forge is actively working on improving the evidence base around recruitment of trial participants; if you would like to collaborate on an embedded study focussed on recruitment strategies please get in touch


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