[Basic principles, design elements, advantages and challenges of emulated target trial].

Cohort studies have unique advantages such as good representation of subjects, large sample size, and long follow-up time, but the difficulty in controlling confounders is the main obstacle to their insufficient causal inference. On the contrary, randomized controlled trial (RCT) research has absolute advantages in controlling confounding factors, but human, material, and ethical aspects limit its organizational implementation. With the accumulation of real-world cohort research data in recent years, emulated target trial (ETT) following the design principles of RCT research in large cohort studies has attracted more attention. ETT research based on cohort data produces more accurate research conclusions and provides new ideas for real-world cohort data analysis. This paper aims to introduce the basic principles, design elements, and advantages and challenges of ETT research to provide a reference for medical researchers to carry out ETT.队列研究往往具有研究对象代表性好、样本量大、随访时间长等独特优势，但混杂因素控制困难是其因果推断不够严密的主要障碍。相反随机对照试验（RCT）研究则在混杂因素的控制上有着绝对的优势，但其组织实施往往会受到人力、物力和伦理等方面的限制。近年来，随着真实世界队列研究数据的积累，在大型队列研究中遵照RCT研究的设计原则开展目标仿真试验（ETT）愈发受到关注。基于队列数据的ETT研究能够得到较为准确的研究结论，也为真实世界队列数据分析提供了新的思路。本文旨在介绍ETT研究的基本原理、设计要素和优缺点，以期为医学研究者开展ETT提供参考。.