title: ROC Estimation from Clustered Data with an Application to Liver Cancer Data.
abstract: In this article, we propose a regression model to compare the performances of different diagnostic methods having clustered ordinal test outcomes. The proposed model treats ordinal test outcomes (an ordinal categorical variable) as grouped-survival time data and uses random effects to explain correlation among outcomes from the same cluster. To compare different diagnostic methods, we introduce a set of covariates indicating diagnostic methods and compare their coefficients. We find that the proposed model defines a Lehmann family and can also introduce a location-scale family of a receiver operating characteristic (ROC) curve. The proposed model can easily be estimated using standard statistical software such as SAS and SPSS. We illustrate its practical usefulness by applying it to testing different magnetic resonance imaging (MRI) methods to detect abnormal lesions in a liver.
authors.affiliation: Department of Information Statistics, Chungbuk National University, Cheongju, Republic of Korea.
authors.forename: Joungyoun
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
authors.forename: Sung-Cheol
authors.initials: SC
authors.lastname: Yun
authors.affiliation: Department of Statistics, Seoul National University, Seoul, Republic of Korea.
authors.forename: Johan
authors.initials: J
authors.lastname: Lim
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
authors.forename: Moo-Song
authors.initials: MS
authors.lastname: Lee
authors.affiliation: Department of Statistics, Seoul National University, Seoul, Republic of Korea.
authors.forename: Won
authors.initials: W
authors.lastname: Son
authors.affiliation: Department of Mathematics and Statistics, University of Maryland, Baltimore County, Baltimore, MD, USA.
authors.forename: DoHwan
authors.initials: D
authors.lastname: Park
keywords: Lehmann family; clustered data; grouped-time survival; ordinal outcomes; random effects; receiver operating characteristic (ROC) curve