What can we learn from trial decliners about improving recruitment? Qualitative study.

backgroundTrials increasingly experience problems in recruiting participants. Understanding the causes of poor recruitment is critical to developing solutions. We interviewed people who had declined a trial of an innovative psychological therapy for depression (REFRAMED) about their response to the trial invitation, in order to understand their decision and identify ways to improve recruitment.

methodsOf 214 people who declined the trial, 35 (16 %) gave permission to be contacted about a qualitative study to explore their decision. Analysis of transcripts of semi-structured interviews was informed by grounded theory.

resultsWe interviewed 20 informants: 14 women and six men, aged 18 to 77 years. Many interviewees had prior experience of research participation and positive views of the trial. Interviewees' decision making resembled a four-stage sequential process; in each stage they either decided not to participate in the trial or progressed to the next stage. In stage 1, interviewees assessed the invitation in the context of their experiences and attitudes; we term those who opted out at this stage 'prior decliners' as they had an established position of declining trials. In stage 2, interviewees assessed their own eligibility; those who judged themselves ineligible and opted out at this stage are termed 'self-excluders'. In stage 3, interviewees assessed their need for the trial therapy and potential to benefit; we term those who decided they did not need the trial therapy and opted out at this stage 'treatment decliners'. In stage 4, interviewees deliberated the benefits and costs of trial participation; those who opted out after judging that disadvantages outweighed advantages are termed 'trial decliners'. Across all stages, most individuals declined because they judged themselves ineligible or not in need of the trial therapy. While 'prior decliners' are unlikely to respond to any trial recruitment initiative, the factors leading others to decline are amenable to amelioration as they do not arise from a rejection of trials or a personal stance.

conclusionsTo improve recruitment in similar trials, the most successful interventions are likely to address patients' assessments of their eligibility and their potential to benefit from the trial treatment, rather than reducing trial burden.

trial registrationInternational Standard Randomised Controlled Trial Number: ISRCTN85784627 . Registration date 10 August 2011.