Methods: MEDLINE (Ovid), Scopus, Cochrane Database of Systematic Reviews (CDSR) and Cochrane Methodology Register, Science Citation Index Expanded (SCI-EXPANDED) and Social Sciences Citation Index (SSCI) within the ISI Web of Science and ERIC were searched in January 2015. Search strategy results were screened by title and abstract, and full text obtained for potentially eligible articles. Studies reporting or evaluating strategies, interventions or methods used to recruit patients were included along with case reports and studies exploring reasons for patient participation or non-participation. Eligible articles were categorised as: systematic reviews, nested randomised controlled trials, and other designs evaluating the effects of recruitment strategies (Level 1); studies that report the use of recruitment strategies without an evaluation of impact (Level 2); or articles reporting factors affecting recruitment without presenting a particular recruitment strategy (Level 3). Articles were also assigned to one, or more, of 42 predefined recruitment domains grouped under six categories.
Results: More than 60,000 records were retrieved by the search, resulting in 56,030 unique titles and abstracts for screening, with a further 23 found through hand searches. 4,570 full text articles were checked; 2,804 were eligible. Six percent of the included articles evaluated the effectiveness of a recruitment strategy (Level 1), with most of these assessing aspects of participant information, either its method of delivery (33%) or its content and format (28%).
Discussion: Recruitment to clinical trials remains a common challenge and an important area for future research. ORRCA provides a searchable, online database of research relevant to recruitment. The project has identified the need for researchers to evaluate their recruitment strategies to improve the evidence base and broaden the narrow focus of existing research to help meet the complex challenges faced by those recruiting to clinical trials.
- Centre for Surgical Research
- Randomised controlled trial
- Clinical trial
- Barriers and facilitators
- Recruitment interventions