Statistics and Risk Management Seminar - 9/6/2014 - 2 p.m.

Monday, 9 June 2014, 2:00 p.m.

Lecturer: Vanda Inácio, Assistant Professor, Department of Statistics, Pontificia Universidad Católica de Chile

Title: "Functional partial area under the curve regression: a metabolic syndrome case study"

Local: Sala de Seminários - Edifício VII
Faculdade de Ciências e Tecnologia, Quinta da Torre, Caparica

Abstract: The statistical evaluation of medical diagnostic tests is of great importance in public health and medical research. New diagnostic tests must be rigorously evaluated to determine their abilities to discriminate between diseased and nondiseased states and it is of crucial importance to understand the covariate influence to determine the optimal and suboptimal populations to perform such tests on. Due to advances in technology, medical diagnostic data have become increasingly complex and, nowadays, applications where measurements are functions, curves, or images are becoming more and more common. We develop non-parametric regression methods for the partial area under the receiver operating characteristic curve, a well-accepted measure of diagnostic test accuracy when only a region of the curve is of interest, for the case where the covariate influencing test's performance is functional. The simulation study shows that our method produces estimates with small bias and small mean squared error. The application of our method to assess the ability of the gamma-glutamyl-transferase to detect women with metabolic syndrome reveals that the nocturnal levels of arterial oxygen saturation of hemoglobin are key to test performance.