Journal of Molecular Biomarkers and Clinical Trials

Impediments to Patient Recruitment in Clinical Trials

*Taylor R Celerion
Department Of Molecular Biomarkers, Spain, Spain

*Corresponding Author:
Taylor R Celerion
Department Of Molecular Biomarkers, Spain, Spain

Published on: 2018-08-10


Recruiting patients into randomized clinical trials (RCTs) remains a serious challenge that may compromise evidence-based medicine’s ability to study treatments. In this narrative review, four main domains affecting recruitment were identified: factors related to the RCT, clinician-related factors, patient-related factors, and influences from the community. Some obstacles to recruitment appear relatively easy to resolve: logistical considerations (for example, studies that pay for the patient’s parking or other expenses), translated forms for non-native speakers, and preparation to deal with particular patient populations (such as pediatric patients or the disabled). Other obstacles relate to deep-seated individual attitudes about research (altruism versus personal safety) and distrust about the medical community and medical organizations. Suboptimal clinical organization and inadequate teamwork among colleagues can also impede recruitment efforts. In some cases, studies may be designed upfront to better accommodate the needs of the prospective patient population, particularly if special populations are involved, and researchers should take into account how attractive their RCT is to the targeted patient population


Clinical study; Clinical trial; Patient enrollment; Patient recruitment; Randomized controlled trial


Randomized controlled trials (RCTs) provide the basis for clinical decision-making in modern evidence-based medicine. Despite their obvious value in determining efficaciousness of various therapies, RCTs are hampered by slow or failing efforts in patient recruitment. In a meta-analysis of RCTs, only 31% could complete enrollment within the planned enrollment period [1]. The majority of RCTs (63%) reported problems specifically in-patient recruitment and 41% had to delay their start because they could not enroll sufficient numbers of patients [1]. In the United Kingdom (UK), the House of Commons Select Committee on Science and Technology 2000 found that less than 5% of adults with solid tumors entered an RCT [2]. The National Cancer Institute estimates that only 4% of eligible patients actually participate in clinical trials and a Center Watch survey found that 90% of clinical trials failed to complete enrollment within their projected timeframe with a mean delay of six weeks [3].