Knowledge Discovery about Quality of Life Changes of Spinal Cord Injury Patients: Clustering Based on Rules by States Karina GIBERT a, 1 , Alejandro GARCÍA-RUDOLPH b , Lluïsa CURCOLL b , Dolors SOLER b , Laura PLA b , José María TORMOS b a Knowledge Engineering and Machine Learning Group, Department of Statistics and Operations Research, Universitat Politecnica de Catalunya, Barcelona, Spain b Institut Guttmann, Hospital de Neurorehabilitació, Badalona, Spain Abstract. In this paper, an integral Knowledge Discovery Methodology, named Clustering based on rules by States, which incorporates artificial intelligence (AI) and statistical methods as well as interpretation-oriented tools, is used for extracting knowledge patterns about the evolution over time of the Quality of Life (QoL) of patients with Spinal Cord Injury. The methodology incorporates the interaction with experts as a crucial element with the clustering methodology to guarantee usefulness of the results. Four typical patterns are discovered by taking into account prior expert knowledge. Several hypotheses are elaborated about the reasons for psychological distress or decreases in QoL of patients over time. The knowledge discovery from data (KDD) approach turns out, once again, to be a suitable formal framework for handling multidimensional complexity of the health domains. Keywords. knowledge discovery from data, decision support and knowledge management, clustering, spinal cord injury, quality of life 1. Introduction Spinal Cord Injury (SCI) is a modern epidemic [1]. Most of SCI cases have a traumatic origin and prevails in young people. Main causes are traffic, occupational and sporting accidents. There are about 1,000 new cases of traumatic SCI per year in Spain; between 140 and 160 in Catalonia. The prevalence of SCI is about 500 persons per million [2]. Considerable progress in the understanding of the pathogenesis and improvements in early recognition and treatments have occurred since Dr. Guttmann times. Currently, the SCI patients have a life expectancy similar to that of the general population, but disability persists throughout the patient’s life. Maintenance or improvement of Quality of Life (QoL) is becoming a main goal, even for the WHO. Furthermore, the scientific community is now accepting that QoL can be formalized as a multidimensional construct depending on different objective as well as subjective aspects [3]. Indeed, in this work it was found that similar physical impairments can be followed by different psychological responses. Thus, it is important to understand the reasons and factors of a 1 Corresponding Author: Ed. C5. Pta 2. Campus Nord, UPC, C. Jordi Girona 1-3, Barcelona 08034; E-mail: karina.gibert@upc.edu. Medical Informatics in a United and Healthy Europe K.-P. Adlassnig et al. (Eds.) IOS Press, 2009 © 2009 European Federation for Medical Informatics. All rights reserved. doi:10.3233/978-1-60750-044-5-579 579