Hepatology department, University Hospital, Angers, France.
Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy.
Liver Int. 2019 Jan;39(1):49-53. doi: 10.1111/liv.13945. Epub 2018 Sep 10.
BACKGROUND & AIMS: Baveno VI criteria enabled the screening of varices needing treatment (VNT) without endoscopy but created confusion by not stating the method used to calculate the 5% missed VNT limit, resulting in different calculations across validation studies. We analysed those calculations to clarify their diagnostic meaning.
(a) Literature review and recalculation of the missed VNT rates according to the three definitions encountered. (b) Contingency table comparison of these latter to determine their diagnostic meanings. (c) Real case analysis. 4/Simulation of variations in the three main statistical descriptors (VNT, missed VNT or spared endoscopies).
Missed VNT rates in the three definitions varied five- to 10-fold across 7 papers. The contingency table showed that the definitions based on VNT prevalence and spared endoscopy as reference corresponded, respectively, to sensitivity and negative predictive value (NPV). The whole population-based definition corresponded to diagnostic accuracy (not pertinent in that setting). Real case analysis showed that concerning liver stiffness, the 95% sensitivity and NPV cut-offs for VNT were, respectively, 14.1 and 26.5 kPa. The VNT-based definition offered a more statistically powerful paired comparison between diagnostic tests, whereas the definition based on spared endoscopies was hampered by an unpaired comparison. Case simulation showed that the VNT-based definition was the most sensitive to descriptor variations.
The definitions of missed VNT rate placing VNT or spared endoscopy as the denominator are appropriate, providing, respectively, sensitivity and NPV for VNT. We privilege the first since it corresponds to the true proportion of missed VNT.
Baveno VI 标准使得无需内镜即可筛查需要治疗的静脉曲张（VNT），但由于未说明计算 5%漏诊 VNT 界限所使用的方法，导致验证研究之间的计算方法不同，从而产生混淆。我们分析了这些计算方法，以阐明其诊断意义。
（a）文献回顾和根据三种遇到的定义重新计算漏诊 VNT 率。（b）通过列联表比较这些定义，以确定其诊断意义。（c）实际病例分析。（c）模拟三种主要统计描述符（VNT、漏诊 VNT 或避免内镜检查）的变化。
三种定义的漏诊 VNT 率在 7 篇论文中差异高达 5 到 10 倍。列联表显示，基于 VNT 患病率和避免内镜检查的定义分别对应于敏感性和阴性预测值（NPV）。基于整个人群的定义对应于诊断准确性（在这种情况下不相关）。实际病例分析表明，对于肝硬度，VNT 的 95%敏感性和 NPV 截断值分别为 14.1 和 26.5 kPa。基于 VNT 的定义提供了更具统计学意义的诊断测试配对比较，而基于避免内镜检查的定义则受到非配对比较的限制。病例模拟表明，基于 VNT 的定义对描述符变化最敏感。
将 VNT 或避免内镜检查作为分母的漏诊 VNT 率定义是合适的，分别提供 VNT 的敏感性和 NPV。我们更倾向于第一个，因为它对应于真正的漏诊 VNT 比例。
