Background: The low recruitment rates into surgical randomized controlled trials (RCTs) threaten the validity of their findings. We reviewed the reasons for nonentry of eligible patients into surgical RCTs that would form the basis for future prospective research.
Methods: A systematic review of the English language literature for studies reporting reasons for nonentry of eligible patients into surgical RCTs and of recommendations made to improve the low recruitment rates.
Results: We reviewed 401 articles, including 94 articles presenting the results of 62 studies: 23 reports of recruitment into real surgical RCTs, 11 surveys of patients regarding hypothetical surgical RCTs, 10 surveys of clinicians and 18 literature reviews. The most frequently reported patient-related reasons for nonentry into surgical RCTs were preference for one form of treatment, dislike of the idea of randomization, and the potential for increased demands. Distrust of clinicians caused by a struggle to understand, explicit refusal of a no-treatment (placebo) arm, and the mere inability to make a decision were frequently reported in studies of real RCTs and patient surveys, but were not emphasized in surveys of clinicians and review articles. Difficulties with informed consent, the complexity of study protocols, and the clinicians' loss of motivation attributable to lack of recognition were the most commonly reported clinician-related reasons.
Conclusions: There seems to be a discrepancy between real reasons for nonentry of eligible patients into surgical RCTS and those perceived by the clinicians, which require further prospective research. A summary and discussion of main recommendations sighted in the literature is presented.