Abstract：
Although randomised controlled trials are considered the gold standard in clinical research, they are not always feasible due to limitations in the study population, challenges in obtaining evidence, high costs and ethical considerations. As a result, single-arm trial designs have emerged as one of the methods to address these issues. Single-arm trials are commonly applied to study advanced-stage cancer, rare diseases, emerging infectious diseases, new treatment methods and medical devices. Single-arm trials have certain ethical advantages over randomised controlled trials, such as providing equitable treatment, respecting patient preferences, addressing rare diseases and timely management of adverse events. While single-arm trials do not adhere to the principles of randomisation and blinding in terms of scientific rigour, they still incorporate principles of control, balance and replication, making the design scientifically reasonable. Compared with randomised controlled trials, single-arm trials require fewer sample sizes and have shorter trial durations, which can help save costs. Compared with cohort studies, single-arm trials involve intervention measures and reduce external interference, resulting in higher levels of evidence. However, single-arm trials also have limitations. Without a parallel control group, there may be biases in interpreting the results. In addition, single-arm trials cannot meet the requirements of randomisation and blinding, thereby limiting their evidence capacity compared with randomised controlled trials. Therefore, researchers consider using single-arm trials as a trial design method only when randomised controlled trials are not feasible.
摘要：
尽管随机对照试验被认为是临床研究的黄金标准，由于研究人群的限制，它们并不总是可行的，在获取证据方面的挑战，高成本和道德考虑。因此,单臂试验设计已成为解决这些问题的方法之一.单臂试验通常用于研究晚期癌症，罕见疾病,新出现的传染病,新的治疗方法和医疗设备。单臂试验比随机对照试验有一定的伦理优势，比如提供公平的待遇，尊重患者的喜好，解决罕见疾病和及时管理不良事件。虽然单臂试验在科学严谨性方面不遵守随机化和致盲的原则，他们仍然包含控制原则，平衡和复制，使设计科学合理。与随机对照试验相比，单臂试验需要更少的样本量和更短的试验持续时间，这可以帮助节省成本。与队列研究相比，单臂试验涉及干预措施和减少外部干扰，导致更高水平的证据。然而,单臂试验也有局限性.如果没有并行控制组，在解释结果时可能存在偏见。此外,单臂试验不能满足随机化和盲法的要求，因此，与随机对照试验相比，限制了他们的证据能力。因此,只有在随机对照试验不可行的情况下,研究者才考虑将单臂试验作为试验设计方法.
