Andishe_ye Amari

Andishe_ye Amari

Increasing the accuracy of classifying diabetic patients in terms of functional limitations using a linear and nonlinear combination of biomarkers: Ramp AUC method

Document Type : Original Article

Authors
1 Master of Science in Biostatistics, Faculty of Medicine, Evidence-Based Medicine Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
2 PhD in Biostatistics, Department of Statistics and Epidemiology, Tabriz University of Medical Sciences, Tabriz, Iran
3 Associate Professor, Medical Education Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
4 PhD in Epidemiology, Department of Statistics and Epidemiology, Tabriz University of Medical Sciences, Tabriz, Iran
Abstract
The area under the Rock curve is a common criterion for evaluating the classification performance of biomarkers. In practice, a biomarker has limited classification power, so to improve the classification performance, we are interested in combining the values ​​of biomarkers linearly and nonlinearly. In this study, while introducing the types of loss functions, the Ramp AUC method and some of its features are introduced as a statistical model based on the area under the Rock curve. This model is presented to combine biomarkers linearly or nonlinearly with the aim of improving the classification performance and minimizing the empirical loss function based on the Ramp AUC loss function. As an applied example, this study used data from 378 diabetic patients referred to the Ardabil and Tabriz diabetes centers in 2014-2015. The RAUC method was used to classify diabetic patients in terms of functional limitation status based on demographic and clinical biomarkers. Model validation was performed using the training and testing method. Based on the results of the experimental group, the area under the curve values ​​obtained for the RAUC model with linear combinations of biomarkers in the form of a linear kernel are 0.81 and with a radial basis function kernel are 1.00. The results indicate the presence of a strong nonlinear pattern in the data, such that nonlinear combinations of biomarkers have higher classification performance than linear combinations.
Keywords

Volume 24, Issue 2
February 2019
Pages 95-103

  • Receive Date 10 May 2025
  • First Publish Date 10 May 2025
  • Publish Date 20 February 2020