Understanding the perspectives of recruiters is key to improving randomised controlled trial enrolment: a qualitative evidence synthesis

BACKGROUND: Recruiting patients to randomised controlled trials (RCTs) is often reported to be challenging, and the evidence base for effective interventions that could be used by staff (recruiters) undertaking recruitment is lacking. Although the experiences and perspectives of recruiters have been widely reported, an evidence synthesis is required in order to inform the development of future interventions. This paper aims to address this by systematically searching and synthesising the evidence on recruiters’ perspectives and experiences of recruiting patients into RCTs. METHODS: A qualitative evidence synthesis (QES) following Thomas and Harden’s approach to thematic synthesis was conducted. The Ovid MEDLINE, CINAHL, EMBASE, PsycInfo, Cochrane Central Register of Controlled Trials, ORRCA and Web of Science electronic databases were searched. Studies were sampled to ensure that the focus of the research was aligned with the phenomena of interest of the QES, their methodological relevance to the QES question, and to include variation across the clinical areas of the studies. The GRADE CERQual framework was used to assess confidence in the review findings. RESULTS: In total, 9316 studies were identified for screening, which resulted in 128 eligible papers. The application of the QES sampling strategy resulted in 30 papers being included in the final analysis. Five overlapping themes were identified which highlighted the complex manner in which recruiters experience RCT recruitment: (1) recruiting to RCTs in a clinical environment, (2) enthusiasm for the RCT, (3) making judgements about whether to approach a patient, (4) communication challenges, (5) interplay between recruiter and professional roles. CONCLUSIONS: This QES identified factors which contribute to the complexities that recruiters can face in day-to-day clinical settings, and the influence recruiters and non-recruiting healthcare professionals have on opportunities afforded to patients for RCT participation. It has reinforced the importance of considering the clinical setting in its entirety when planning future RCTs and indicated the need to better normalise and support research if it is to become part of day-to-day practice. TRIAL REGISTRATION: PROSPERO CRD42020141297 (registered 11/02/2020). SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13063-022-06818-4.