Basel Institute for Clinical Epidemiology and Biostatistics, Department of Clinical Research, University of Basel and University Hospital Basel, Spitalstrasse 12, 4031, Basel, Switzerland.
Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada.
Trials. 2021 Nov 25;22(1):844. doi: 10.1186/s13063-021-05818-0.
Poor participant recruitment is the most frequent reason for premature discontinuation of randomized clinical trials (RCTs), particularly if they are investigator-initiated. The aims of this qualitative study were to investigate (1) the views of clinical trial stakeholders from three different countries regarding reasons for recruitment failure in RCTs and (2) how these compare and contrast with the causes identified in a previous systematic review of RCT publications.
From August 2015 to November 2016, we conducted 49 semi-structured interviews with a purposive sample of clinical trial stakeholders. This included investigators based in Germany (n = 9), Switzerland (n = 6) and Canada (n = 1) with personal experience of a discontinued RCT and 33 other stakeholders (e.g., representatives of ethics committees, clinical trial units, pharmaceutical industry) in Switzerland. Individual semi-structured qualitative interviews were conducted and analyzed using thematic analysis.
Interviewees identified a total of 29 different reasons for recruitment failure. Overoptimistic recruitment estimates, too narrow eligibility criteria, lack of engagement of recruiters/trial team, lack of competence/training/experience of recruiters, insufficient initial funding, and high burden for trial participants were mentioned most frequently. The interview findings largely confirm the previous systematic review on published reasons for recruitment failure. However, eight new reasons for recruitment failure were identified in the interviews, which led to the checklist of reasons for recruitment failure being revised and a new category describing research environment-related factors being added.
This study highlights the diversity of often interlinked reasons for recruitment failure in RCTs. Integrating the findings of this interview study with a previous systematic review of RCT publications led to a comprehensive, structured checklist of empirically-informed reasons for recruitment failure. The checklist may be useful to guide further research on interventions to improve participant recruitment in RCTs and helpful for trial investigators, research ethics committees, and funding agencies when assessing trial feasibility with respect to recruitment.
参与者招募不足是导致随机临床试验 (RCT) 提前终止的最常见原因，尤其是如果这些试验是由研究者发起的。本研究的目的是从三个不同国家的临床试验利益相关者的角度调查：(1) 导致 RCT 招募失败的原因，以及 (2) 与之前 RCT 文献系统综述中确定的原因相比，这些原因有何异同。
2015 年 8 月至 2016 年 11 月，我们对有过中止 RCT 经验的德国（n = 9）、瑞士（n = 6）和加拿大（n = 1）的研究者和瑞士的 33 名其他利益相关者（如伦理委员会代表、临床试验单位、制药行业代表）进行了 49 次半结构化访谈。采用主题分析法对个人半结构化定性访谈进行分析。
受访者共确定了 29 种不同的招募失败原因。过高的招募估计、过于狭窄的纳入标准、招募人员/试验团队缺乏参与、招募人员缺乏能力/培训/经验、初始资金不足以及试验参与者负担过重等被提及最多。访谈结果在很大程度上证实了之前对发表的招募失败原因的系统综述。然而，访谈中还确定了 8 种新的招募失败原因，这导致对招募失败原因检查表进行了修订，并增加了一个描述研究环境相关因素的新类别。
本研究强调了 RCT 中招募失败的原因通常具有多样性，且往往相互关联。将本访谈研究的结果与之前对 RCT 文献的系统综述相结合，形成了一个全面、结构化的、基于经验的招募失败原因检查表。该检查表可用于指导进一步研究改善 RCT 中参与者招募的干预措施，并有助于试验研究者、研究伦理委员会和资助机构在评估招募可行性时使用。
