Next week’s Departmental seminar will be given by Vanda Inacio De Carvalho (The University of Edinburgh).
The seminar will be followed by tea in the Common Room, which the speaker will join us for too.
-----------------------------------------------------------------------------------------------
Time and date: Thursday 9th November, 2-3pm
In-person location: 1-19 Torrington Place, B09
Link to join online: contact ( [log in to unmask] )
-----------------------------------------------------------------------------------------------
Title: Induced nonparametric ROC surface regression
Abstract: The receiver operating characteristic (ROC) surface is a popular tool for evaluating the discriminatory ability of diagnostic tests, measured on a continuous scale, when there are three ordered disease groups. Motivated by the impact that covariates may have on the diagnostic accuracy, and to safeguard against model misspecification, we develop a flexible model for conducting inference about the covariate-specific ROC surface and its functionals. Specifically, we postulate a location-scale regression model for the test outcomes in each of the three disease groups where the mean and variance functions are estimated through penalised-splines, while the distribution of the error term is estimated via a smoothed version of the empirical cumulative distribution function of the standardised residuals. Our simulation study shows that our approach successfully recovers both the true covariate-specific volume under the surface and the optimal pair of thresholds used for classification in a variety of conceivable scenarios. Our methods are motivated by and applied to data derived from an Alzheimer's disease study and we seek to assess the accuracy of several potential biomarkers to distinguish between individuals with normal cognition, mild cognitive impairment, and dementia and how this discriminatory ability may change with age and gender.
Dr. F. Javier Rubio
Lecturer (Assistant Professor)
Department of Statistical Science
University College London
https://sites.google.com/site/fjavierrubio67/
You may leave the list at any time by sending the command
SIGNOFF allstat
to [log in to unmask], leaving the subject line blank.
|