Eszter Ilona Lohn: Estimating the clinical score of coma patients - a comparison of model selection methods

Adviser: Prof. Dr. Werner Stahel

March 2012

Abstract:

The aim of this thesis is to explore the possibility of estimating coma patients' clinical awareness score by objective clinical measurements, in order to substitute the rather subjective doctors' examination which is expensive and time consuming. A comparison is made on variable selection and model fitting methods by cross-validation. The basic analysis is extended towards block subset analysis, alternative cross-validation schemes and analyzing the dynamics of the clinical score. As only a small sample is available, the phenomenon of over fitting is a serious concern throughout the analysis, which is seen through the difference of in-sample and cross-validated model fits. In general we observe that low-variance (higher bias) methods perform better on this sample size. In the end it is concluded that based on this sample the clinical measurements contain little information about the clinical awareness score.