Solomon Nadia, Fields Paul J, Tamarozzi Francesca, Brunetti Enrico, Macpherson Calum N L
School of Medicine, St. George's University, St. George's, Grenada.
Windward Islands Research and Education Foundation (WINDREF), St. George's, Grenada.
Am J Trop Med Hyg. 2017 Mar;96(3):686-691. doi: 10.4269/ajtmh.16-0659. Epub 2017 Apr 6.
Cystic echinococcosis (CE), a parasitic zoonosis, results in cyst formation in the viscera. Cyst morphology depends on developmental stage. In 2003, the World Health Organization (WHO) published a standardized ultrasound (US) classification for CE, for use among experts as a standard of comparison. This study examined the reliability of this classification. Eleven international CE and US experts completed an assessment of eight WHO classification images and 88 test images representing cyst stages. Inter- and intraobserver reliability and observer performance were assessed using Fleiss' and Cohen's kappa. Interobserver reliability was moderate for WHO images (κ = 0.600, < 0.0001) and substantial for test images (κ = 0.644, < 0.0001), with substantial to almost perfect interobserver reliability for stages with pathognomonic signs (CE1, CE2, and CE3) for WHO (0.618 < κ < 0.904) and test images (0.642 < κ < 0.768). Comparisons of expert performances against the majority classification for each image were significant for WHO (0.413 < κ < 1.000, < 0.005) and test images (0.718 < κ < 0.905, < 0.0001); and intraobserver reliability was significant for WHO (0.520 < κ < 1.000, < 0.005) and test images (0.690 < κ < 0.896, < 0.0001). Findings demonstrate moderate to substantial interobserver and substantial to almost perfect intraobserver reliability for the WHO classification, with substantial to almost perfect interobserver reliability for pathognomonic stages. This confirms experts' abilities to reliably identify WHO-defined pathognomonic signs of CE, demonstrating that the WHO classification provides a reproducible way of staging CE.
囊性棘球蚴病(CE)是一种寄生虫人畜共患病,可导致内脏形成囊肿。囊肿形态取决于发育阶段。2003年,世界卫生组织(WHO)发布了CE的标准化超声(US)分类,供专家用作比较标准。本研究检验了该分类的可靠性。11位国际CE和US专家对代表囊肿阶段的8张WHO分类图像和88张测试图像进行了评估。使用Fleiss和Cohen的kappa评估观察者间和观察者内的可靠性以及观察者表现。WHO图像的观察者间可靠性为中等(κ = 0.600,P < 0.0001),测试图像的观察者间可靠性为实质性(κ = 0.644,P < 0.0001),对于WHO(0.618 < κ < 0.904)和测试图像(0.642 < κ < 0.768)中具有特征性体征的阶段(CE1、CE2和CE3),观察者间可靠性为实质性至几乎完美。专家表现与每张图像的多数分类的比较,对于WHO(0.413 < κ < 1.000,P < 0.005)和测试图像(0.718 < κ < 0.905,P < 0.0001)具有显著性;观察者内可靠性对于WHO(0.520 < κ < 1.000,P < 0.005)和测试图像(0.690 < κ < 0.896,P < 0.0001)具有显著性。研究结果表明,WHO分类的观察者间可靠性为中等至实质性,观察者内可靠性为实质性至几乎完美,具有特征性体征的阶段观察者间可靠性为实质性至几乎完美。这证实了专家可靠识别WHO定义的CE特征性体征的能力,表明WHO分类提供了一种可重复的CE分期方法。