Failure to recruit sufficient numbers of participants to randomized controlled trials is a common and serious problem. This problem may be additionally acute in music therapy research.
To use the experience of conducting a large randomized controlled trial of music therapy for young people with emotional and behavioral difficulties to illustrate the strategies that can be used to optimize recruitment; to report on the success or otherwise of those strategies; and to draw general conclusions about the most effective approaches.
Review of the methodological literature, and a narrative account and realist analysis of the recruitment process.
The strategies adopted led to the achievement of the recruitment target of 250 subjects, but only with an extension to the recruitment period. In the pre-protocol stage of the research, these strategies included the engagement of non-music therapy clinical investigators, and extensive consultation with clinical stakeholders. In the protocol development and initial recruitment stages, they involved a search of systematic reviews of factors leading to under-recruitment and of interventions to promote recruitment, and the incorporation of their insights into the research protocol and practices. In the latter stages of recruitment, various stakeholders including clinicians, senior managers and participant representatives were consulted in an attempt to uncover the reasons for the low recruitment levels that the research was experiencing.
The primary mechanisms to promote recruitment are education, facilitation, audit and feedback, and time allowed. The primary contextual factors affecting the effectiveness of these mechanisms are professional culture and organizational support.