自2019年12月新型冠状病毒肺炎（Coronavirus Disease 2019, COVID-19）暴发以来，已有大量相关临床研究完成注册或已启动。然而，不同研究间临床结局指标存在显著的异质性，同时一些不关键的指标会造成研究资源的浪费。本研究旨在构建COVID-19临床试验核心结局指标集（core outcome set, COS），为相关临床研究方案设计、开展和证据转化提供参考。本研究的实施参照《有效性试验核心结局指标（COMET）手册》（1.0版），研究组成员包括呼吸系统和危重医学、中医学、循证医学、临床药理学、统计学专家以及医学杂志编辑等。通过检索临床试验注册网站（chictr.org.cn和clinicaltrials.gov）中COVID-19相关临床研究方案，提取方案中的结局指标，形成指标池。78个COVID-19临床试验方案纳入研究，收集结局指标259个，合并规范后确定132个结局指标，涉及7个指标域。经遴选，形成了包括58个结局指标在内的初始指标清单。经过两轮德尔菲调查和一轮共识会议，最终确立针对COVID-19不同临床分型的核心指标集（COS-COVID）。COS-COVID包括1个轻型指标（病毒核酸检测转阴时间）、4个普通型指标（住院时间、复合事件发生率、临床症状积分和病毒核酸检测转阴时间）、5个重型指标（复合事件发生率、住院时间、PaO₂/FiO₂、机械通气时间和病毒核酸检测转阴时间）、1个危重型指标（全因死亡率）及1个康复期指标（肺功能）。COS-COVID作为目前临床评价COVID-19干预效果最具临床价值及操作性的指标集合，对证据评估和决策具有重要意义。随着对疾病认知的不断深入和COS-COVID应用的反馈，课题组将对本核心指标集进行进一步完善并更新。

Since its outbreak in December 2019, a series of clinical trials on coronavirus disease 2019 (COVID-19) have been registered or carried out. However, the significant heterogeneity and less critical outcomes of such trials may be leading to a waste of research resources. This study aimed to develop a core outcome set (COS) for clinical trials on COVID-19 in order to tackle the outcome issues. The study was conducted according to the Core Outcome Measures in Effectiveness Trials (COMET) Handbook: Version 1.0, a guideline for COS development. A research group was set up that included experts in respiratory and critical medicine, traditional Chinese medicine (TCM), evidence-based medicine, clinical pharmacology, and statistics, in addition to medical journal editors. Clinical trial registry websites (www.chictr.org.cn and clinicaltrials.gov) were searched to retrieve clinical trial protocols and outcomes in order to form an outcome pool. A total of 78 clinical trial protocols on COVID-19 were included and 259 outcomes were collected. After standardization, 132 outcomes were identified within seven different categories, of which 58 were selected to develop a preliminary outcome list for further consensus. After two rounds of Delphi survey and one consensus meeting, the most important outcomes for the different clinical classifications of COVID-19 were identified and determined to constitute the COS for clinical trials on COVID-19 (COS-COVID). The COS-COVID includes one outcome for the mild type (time to 2019 novel coronavirus (2019-nCoV) reverse transcription-polymerase chain reaction (RT-PCR) negativity), four outcomes for the ordinary type (length of hospital stay, composite events, score of clinical symptoms, and time to 2019-nCoV RT-PCR negativity), five outcomes for the severe type (composite events, length of hospital stay, arterial oxygen partial pressure (PaO₂)/fraction of inspired oxygen (FiO₂), duration of mechanical ventilation, and time to 2019-nCoV RT-PCR negativity), one outcome for critical type (all-cause mortality), and one outcome for rehabilitation period (pulmonary function). The COS-COVID is currently the most valuable and practical clinical outcome set for the evaluation of intervention effect, and is useful for evidence assessment and decision-making. With a deepening understanding of COVID-19 and application feedback, the COS-COVID should be continuously updated.