Strategies to improve recruitment to randomised trials

Abstract

The literature on interventions to improve recruitment to trials has plenty of variety but little depth. Only 3 of 72 comparisons are supported by high-certainty evidence according to GRADE: having an open trial and using telephone reminders to non-responders to postal interventions both increase recruitment; a specialised way of developing participant information leaflets had little or no effect. The methodology research community should improve the evidence base by replicating evaluations of existing strategies, rather than developing and testing new ones.

The research burden of randomized controlled trial participation: a systematic thematic synthesis of qualitative evidence

“…Qualitative studies embedded or associated with RCTs could help understand patients' experiences of RCT participation and the possible burdens encountered. To our knowledge, there are systematic reviews of qualitative studies to identify barriers and facilitators to recruitment and retention in RCTs [5][6][7]; however, no review yet has specifically explored patients' research burden.…”

Low risk pragmatic trials do not always require participants’ informed consent

“…Current evidence around modifications to the consent process or format shows little or no effect on recruitment compared with standard written consent 24. Electronic informed consent25 is starting to be used26 but could lead to a non-representative group of participants.…”

A telephone reminder to enhance adherence to interventions in cardiovascular randomized trials: A protocol for a study within a trial (SWAT)

“…A great deal of effort is often expended in recruiting participants to randomized trials 17 . Following the challenge of recruiting the required number of participants, there is the problem of ensuring that all participants remain in the trial and adhere to the trial intervention as required 6,11 .…”

“…A great deal of effort is often expended in recruiting participants to randomized trials. 17 Following the challenge of recruiting the required number of participants, there is the problem of ensuring that all participants remain in the trial and adhere to the trial intervention as required. 6,11 Nonadherence to the trial intervention has serious implications, resulting in decreasing the statistical power of the study, impacting negatively on the trial outcomes and increasing the risk of attrition bias due to incomplete data.…”

“…16 Telephone reminders to nonresponders were effective in increasing recruitment to trials. 17 As yet, this strategy has not been tested to improve adherence to trial interventions. Telephone reminder intervention could have a greater effect on nonintentional nonadherence in CR trials.…”