整群随机试验

整群随机试验在临床研究中应用较为广泛，其以“群”为随机单位，一个群中的所有个体接受相同的干预，因此与以个体为随机单位的随机对照试验相比，整群随机试验能够减少“沾染”，组织实施更为简便，更适合公共卫生措施评价和医疗质量改进研究。然而，整群随机试验组间可比性欠佳，存在设计效应，因此需要较大的样本量。本文将从整群随机试验的历史渊源、基本概念、研究设计、应用场景和案例解读、报告规范等方面进行全面总结，以期帮助临床研究者认识、了解、掌握此类研究设计。

Cluster Randomized Trials

Cluster randomized trials are widely used in clinical research, which use clusters as random unit, and all individuals in a cluster receive the same intervention. Therefore, compared with randomized controlled trials with individuals as random unit, cluster randomized trials can reduce "contamination", which is easier to organize, and is very suitable for public health measures evaluation and medical quality improvement research. However, cluster randomized trials have a design effect and poor comparability between clusters, and need a larger sample size. This article provided a comprehensive overview of cluster randomized trials in terms of history, basic concept, study design, application scenarios, cases analysis, and reporting standards, in order to help clinical researchers understand and master this type of study design.