Department of Gastroenterology, São João University Hospital Center (CHUSJ), Porto, Portugal.
Department of Biomedicine, Unit of Pharmacology and Therapeutics, Faculty of Medicine, University of Porto, Porto, Portugal.
United European Gastroenterol J. 2022 Feb;10(1):54-72. doi: 10.1002/ueg2.12183. Epub 2021 Dec 14.
Ulcerative colitis (UC) has been the focus of numerous observational studies over the years and a common strategy employed in their design is the use of composite and aggregate outcomes.
This systematic review and meta-analysis aims to identify composite and aggregate outcomes of observational studies in UC and to evaluate how the number and type of variables included and the length of follow-up affect the frequency of patients that achieve these outcomes.
A systematic literature search was carried out using MEDLINE [via PubMed], Scopus, and Web of Science online databases. Observational studies that included UC patients and reported composite or aggregate outcomes were identified. A set of variables considered to be representative of progressive or disabling UC was defined, the proportion of patients attaining the outcomes was determined and a random-effects meta-analysis was performed by dividing the identified studies into subgroups according to different criteria of interest.
A total of 10,264 records were identified in the systematic search, of which 33 were retained for qualitative analysis and 20 were included in the meta-analysis. The mean frequency for composite outcomes was 0.363 [95% confidence interval (CI) 0.323-0.403]. The frequency of composite outcome for the subgroup of studies that included the variable "Biologics" was significantly higher than for those in which this variable was not reported [0.410; 95% CI 0.364-0.457 versus 0.298; 95% CI 0.232-0.364; p = 0.006]. Composite outcomes were also more frequent as the follow-up duration increased.
The frequency of composite outcomes in observational studies of UC is dependent on the specific identity of the variables being reported. Moreover, longer follow-up periods are associated with higher frequencies of composite outcomes. The evidence provided here is useful for the design of future observational studies of UC that aim to maximize the frequency of patients that achieve composite outcomes.
溃疡性结肠炎（UC）多年来一直是众多观察性研究的焦点，其设计中常用的一种策略是使用复合和综合结局。
本系统评价和荟萃分析旨在确定 UC 观察性研究中的复合和综合结局，并评估纳入变量的数量和类型以及随访时间的长短如何影响达到这些结局的患者频率。
使用 MEDLINE [通过 PubMed]、Scopus 和 Web of Science 在线数据库进行系统文献检索。确定纳入 UC 患者并报告复合或综合结局的观察性研究。定义了一组被认为是进展性或致残性 UC 的代表性变量，确定了达到结局的患者比例，并通过按不同感兴趣的标准将确定的研究分为亚组，进行随机效应荟萃分析。
系统搜索共确定了 10264 条记录，其中 33 条用于定性分析，20 条用于荟萃分析。复合结局的平均频率为 0.363[95%置信区间（CI）0.323-0.403]。纳入“生物制剂”变量的研究亚组的复合结局频率明显高于未报告该变量的研究亚组[0.410；95%CI 0.364-0.457 与 0.298；95%CI 0.232-0.364；p=0.006]。随着随访时间的延长，复合结局的频率也更高。
UC 观察性研究中复合结局的频率取决于所报告变量的具体特征。此外，较长的随访时间与复合结局的频率更高相关。此处提供的证据对于设计旨在最大限度提高达到复合结局的患者频率的 UC 观察性研究有用。
