BACKGROUND: The area under the receiver operating characteristic (ROC) curve is widely used as an estimate of the diagnostic value for fibrosis markers. Biopsy length and fragmentation are known as risk factors of false positive or false negative of biopsy but their quantitative impact on area under the receiver operating characteristic curve variability has not been assessed. AIM: To assess these relationships to better compare the fibrosis markers. METHODS: The area under the ROC curves of FibroTest for the diagnosis of fibrosis was estimated in patients with chronic hepatitis C using an integrated database including 1312 patients with FibroTest and biopsy. To take into account the biopsy length, we used two adjustment factors: one in which an observed area under the ROC curve could be adjusted according to the relative area under the receiver operating characteristic curve of a biopsy of a given length vs. the entire liver and one taking into account the prevalence of each fibrosis stage defining advanced and non-advanced fibrosis. RESULTS: The mean biopsy length was smaller for cirrhosis (F4, 16 mm) vs. F3, (18 mm, P=0.01) and F0 (19 mm, P=0.01). The mean number of fragments was higher for cirrhosis (F4=4.1 fragments) vs. all the other stages (F0=1.9, F1=1.9, F2=1.9, F3=2.3; P<0.001 vs. F4). The FibroTest area under the ROC curves for the diagnosis of advanced fibrosis, adjusted for stages' prevalence, ranged from 0.80 to 0.98 depending on biopsy length and fragmentation, respectively. CONCLUSION: The comparison of the area under the ROC curves of fibrosis markers should take into account the biopsy length and fragmentation.
BACKGROUND: The area under the receiver operating characteristic (ROC) curve is widely used as an estimate of the diagnostic value for fibrosis markers. Biopsy length and fragmentation are known as risk factors of false positive or false negative of biopsy but their quantitative impact on area under the receiver operating characteristic curve variability has not been assessed. AIM: To assess these relationships to better compare the fibrosis markers. METHODS: The area under the ROC curves of FibroTest for the diagnosis of fibrosis was estimated in patients with chronic hepatitis C using an integrated database including 1312 patients with FibroTest and biopsy. To take into account the biopsy length, we used two adjustment factors: one in which an observed area under the ROC curve could be adjusted according to the relative area under the receiver operating characteristic curve of a biopsy of a given length vs. the entire liver and one taking into account the prevalence of each fibrosis stage defining advanced and non-advanced fibrosis. RESULTS: The mean biopsy length was smaller for cirrhosis (F4, 16 mm) vs. F3, (18 mm, P=0.01) and F0 (19 mm, P=0.01). The mean number of fragments was higher for cirrhosis (F4=4.1 fragments) vs. all the other stages (F0=1.9, F1=1.9, F2=1.9, F3=2.3; P<0.001 vs. F4). The FibroTest area under the ROC curves for the diagnosis of advanced fibrosis, adjusted for stages' prevalence, ranged from 0.80 to 0.98 depending on biopsy length and fragmentation, respectively. CONCLUSION: The comparison of the area under the ROC curves of fibrosis markers should take into account the biopsy length and fragmentation.
Authors: Keyur Patel; Mireen Friedrich-Rust; Yoav Lurie; Mircea Grigorescu; Carol Stanciu; Chuan-Mo Lee; Eugene R Schiff; Dieter Häussinger; Michael P Manns; Guido Gerken; Isabelle Colle; Michael Torbenson; Erik Pulkstenis; G Mani Subramanian; John G McHutchison; Stefan Zeuzem Journal: World J Gastroenterol Date: 2011-11-07 Impact factor: 5.742
Authors: Robert J Fontana; Jules L Dienstag; Herbert L Bonkovsky; Richard K Sterling; Deepa Naishadham; Zachary D Goodman; Anna S F Lok; Elizabeth C Wright; Grace L Su Journal: Gut Date: 2010-07-30 Impact factor: 23.059
Authors: Tinsay A Woreta; Catherine G Sutcliffe; Shruti H Mehta; Todd T Brown; Yvonne Higgins; David L Thomas; Michael S Torbenson; Richard D Moore; Mark S Sulkowski Journal: Gastroenterology Date: 2010-12-04 Impact factor: 22.682
Authors: Beom Kyung Kim; Kwang Hyub Han; Jun Yong Park; Sang Hoon Ahn; Chae Yoon Chon; Ja Kyung Kim; Yong Han Paik; Kwan Sik Lee; Young Nyun Park; Do Young Kim Journal: Dig Dis Sci Date: 2009-12-04 Impact factor: 3.199