Poor recruitment to randomised controlled trials (RCTs) is a widespread problem. Provision of interventions aimed at supporting or incentivising clinicians may improve recruitment to RCTs.
To quantify the effects of strategies aimed at improving the recruitment activity of clinicians in RCTs, complemented with a synthesis of qualitative evidence related to clinicians' attitudes towards recruiting to RCTs.
A systematic review of English and non-English articles identified from: The Cochrane Library, Ovid MEDLINE, Ovid EMBASE, Ovid PsycINFO, Ebsco CINAHL, Index to Theses and Open SIGLE from 2001 to March 2011. Additional reports were identified through citation searches of included articles.
Study eligibility criteria
Quantitative studies were included if they evaluated interventions aimed at improving the recruitment activity of clinicians or compared recruitment by different groups of clinicians. Information about host trial, study design, participants, interventions, outcomes and host RCT was extracted by one researcher and checked by another. Studies that met the inclusion criteria were assessed for quality using a standardised tool, the Effective Public Health Practice Project tool. Qualitative studies were included if they investigated clinicians' attitudes to recruiting patients to RCTs. All results/findings were extracted, and content analysis was carried out. Overarching themes were abstracted, followed by a metasummary analysis. Studies that met the inclusion criteria were assessed for quality using the Critical Appraisal Skills Programme qualitative checklist.
Data extraction was carried out by one researcher using predefined data fields, including study quality indicators, and verified by another.
Eight quantitative studies were included describing four interventions and a comparison of recruiting clinicians. One study was rated as strong, one as moderate and the remaining six as weak when assessed for quality using the Effective Public Health Practice Project tool. Effective interventions included the use of qualitative research to identify and overcome barriers to recruitment, reduction of the clinical workload associated with participation in RCTs and the provision of extra training and protected research time. Eleven qualitative studies were identified, and eight themes were abstracted from the data: understanding of research, communication, perceived patient barriers, patient–clinician relationship, effect on patients, effect on clinical practice, individual benefits for clinicians and methods associated with successful recruitment. Metasummary analysis identified the most frequently reported subthemes to be: difficulty communicating trial methods, poor understanding of research and priority given to patient well-being. Overall, the qualitative studies were found to be of good quality when assessed using the Critical Appraisal Skills Programme checklist.
There were few high-quality trials that tested interventions to improve clinicians' recruitment activity in RCTs. The most promising intervention was the use of qualitative methods to identify and overcome barriers to clinician recruitment activity. More good quality studies of interventions are needed to add to the evidence base. The metasummary of qualitative findings identified understanding and communicating RCT methods as a key target for future interventions to improve recruitment. Reinforcement of the potential benefits, both for clinicians and for their patients, could also be a successful factor in improving recruitment. A bias was found towards investigating barriers to recruitment, so future work should also encompass a focus on successfully recruiting trials.
A systematic review to identify and synthesise evidence of evaluations of interventions aimed at improving clinician recruitment activity in RCTs, and evidence of clinicians' attitudes towards recruiting to RCTs.
Evidence-based recruitment interventions aimed at supporting/incentivising clinicians are necessary for future RCTs to recruit successfully. However, evidence of successful interventions is currently limited, and interventions are being used that have limited evidential grounding. The most promising intervention identified by this review was the use of qualitative methods embedded in host RCTs to define appropriate methods, targeted at clinicians, relevant to the context of the individual studies.
The review of qualitative evidence identified a number of themes relating to clinicians' attitudes towards recruitment to RCTs. The metasummary isolated targets for future interventions aimed at improving clinicians' recruitment activity. Of particular interest were communication of trial methods, education to remove misunderstanding of trial methods and reinforcement of the potential benefits of RCTs, both for clinicians and for their patients.
Strengths and limitations of this study
This review encompasses both quantitative and qualitative evidence regarding clinician involvement in recruiting to RCTs. As such, it highlights the available evidence, successful and unsuccessful interventions, areas of uncertainty and also targets for the design of future interventions.
Qualitative data were managed and synthesised according to a set methodology and are therefore a step beyond simple narrative review. Qualitative metasummary can be the final product of a synthesis project or used as the initial step in a metasynthesis project. The purpose of qualitative metasummary was to determine how frequently each abstracted thematic finding occurred in the included studies. Qualitative metasummary is appropriate for synthesising studies that are thematic summaries or surveys of data.
The quality of evidence varied, and the review includes a wide range of study designs, making comparisons of interventions difficult. It is clear that RCTs of trial recruitment interventions are perceived to be difficult to carry out, so other study designs are commonly used. RCTs of recruitment interventions should be encouraged in order to increase the quality of currently available evidence.
Methodological challenges included designing a broad search to encompass qualitative and quantitative research, quality assessment of various quantitative study designs by one set of criteria and standardising the data extraction and synthesis of qualitative evidence. There are no set guidelines regarding the synthesis of qualitative and quantitative evidence, but it is clear that for many review questions limiting the included study designs would lead to empty reviews.