El-Kotob Rasha, Giangregorio Lora M
1Department of Kinesiology, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1 Canada.
2Brain and Spinal Cord Rehabilitation Program, Toronto Rehabilitation Institute, University Health Network, 520 Sutherland Dr, Toronto, ON M4G 3V9 Canada.
Pilot Feasibility Stud. 2018 Aug 14;4:137. doi: 10.1186/s40814-018-0326-0. eCollection 2018.
Clinical trials of physical activity and rehabilitation interventions can be challenging. Pilot or feasibility studies can be conducted prior to a definitive randomized controlled trial (RCT), to improve the chances of conducting a high-quality RCT of a physical activity intervention.
Physical activity interventions or trials present unique challenges at the population, intervention, comparator and outcome levels. At each level, we present guidance for researchers on the design considerations for pilot or feasibility studies of physical activity interventions. When it comes to defining study population, physical activity trials often exclude participants with certain health conditions or other characteristics (e.g., age, gender) because of uncertainty of the safety of the exercise intervention or presumed differences in responsiveness, at the expense of trial generalizability. A pilot trial could help investigators determine refined inclusion and exclusion criteria to balance safety, adequate recruitment, and generalizability. At the intervention level, because exercise can be a complex intervention, pilot trials allow investigators to evaluate participant adherence and instructor fidelity to the intervention and participant experience. At the comparator level, control group dissatisfaction and post-randomization drop-out can occur, because of the desire to be randomized to the exercise group, and the difficulty with blinding to group allocation; an active control or deception could be used. Finally, at the outcome level, there should be an emphasis on the pilot or feasibility outcomes such as recruitment rate, adherence to exercise, and retention or fidelity, than the efficacy of the exercise intervention.
Physical activity and rehabilitation researchers can use pilot and feasibility studies to enhance the rigor of future trials, while also publishing the results of their pilot work to move the field forward. Researchers in this field are encouraged to use published reporting guidelines for pilot and feasibility studies and to consider the challenges discussed in this paper.
身体活动和康复干预的临床试验可能具有挑战性。在进行确定性随机对照试验（RCT）之前，可以先开展试点或可行性研究，以提高进行高质量身体活动干预RCT的几率。
身体活动干预或试验在人群、干预措施、对照和结果层面都存在独特的挑战。在每个层面，我们都为研究人员提供了有关身体活动干预试点或可行性研究设计考量的指导。在定义研究人群时，由于运动干预安全性存在不确定性或假定反应性存在差异，身体活动试验通常会排除患有某些健康状况或具有其他特征（如年龄、性别）的参与者，这是以试验的普遍性为代价的。一项试点试验可以帮助研究人员确定更精确的纳入和排除标准，以平衡安全性、充足的招募人数和普遍性。在干预措施层面，由于运动可能是一种复杂的干预措施，试点试验使研究人员能够评估参与者的依从性以及指导者对干预措施和参与者体验的忠实度。在对照层面，由于希望被随机分配到运动组，以及难以对分组情况进行设盲，可能会出现对照组不满和随机分组后退出的情况；可以采用积极对照或欺骗手段。最后，在结果层面，应更强调试点或可行性结果，如招募率、运动依从性以及留存率或忠实度，而非运动干预的效果。
身体活动和康复研究人员可以利用试点和可行性研究来提高未来试验的严谨性，同时也公布其试点工作的结果，以推动该领域的发展。鼓励该领域的研究人员使用已发表的试点和可行性研究报告指南，并考虑本文中讨论的挑战。
