title: Expert Reliability for the World Health Organization Standardized Ultrasound Classification of Cystic Echinococcosis.
abstract: 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,P< 0.0001) and substantial for test images (κ = 0.644,P< 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,P< 0.005) and test images (0.718 < κ < 0.905,P< 0.0001); and intraobserver reliability was significant for WHO (0.520 < κ < 1.000,P< 0.005) and test images (0.690 < κ < 0.896,P< 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.
authors.affiliation: School of Medicine, St. George's University, St. George's, Grenada.|Windward Islands Research and Education Foundation (WINDREF), St. George's, Grenada.
authors.forename: Nadia
authors.initials: N
authors.lastname: Solomon
authors.affiliation: Windward Islands Research and Education Foundation (WINDREF), St. George's, Grenada.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Fields
authors.affiliation: WHO Collaborating Centre for Clinical Management of Cystic Echinococcosis, University of Pavia, Pavia, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Tamarozzi
authors.affiliation: Department of Infectious Diseases, San Matteo Hospital Foundation, Pavia, Italy.|WHO Collaborating Centre for Clinical Management of Cystic Echinococcosis, University of Pavia, Pavia, Italy.
authors.forename: Enrico
authors.initials: E
authors.lastname: Brunetti
authors.affiliation: School of Veterinary Medicine, St. George's University, St. George's, Grenada.|School of Medicine, St. George's University, St. George's, Grenada.|Windward Islands Research and Education Foundation (WINDREF), St. George's, Grenada.
authors.forename: Calum N L
authors.initials: CNL
authors.lastname: Macpherson
mesh_terms: D004443:Echinococcosis / Q000145:classification* / Q000000981:diagnostic imaging* / Q000469:parasitology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D015588:Observer Variation; D015203:Reproducibility of Results; D014463:Ultrasonography / Q000592:standards*; D014944:World Health Organization