International Journal on Artificial Intelligence Tools Vol. XX, No. X (2015) 1–9  World Scientific Publishing Company 1 OSTEOPOROSIS DETECTION USING MACHINE LEARNING TECHNIQUES AND FEATURE SELECTION THEODOROS ILIOU Cultural Technology and Communication Dpt, Social Science School, University of the Aegean Mytilene, 81100, Lesvos island,Greece th.iliou@ct.aegean.gr CHRISTOS-NIKOLAOS ANAGNOSTOPOULOS Cultural Technology and Communication Dpt, Social Science School, University of the Aegean Mytilene, 81100, Lesvos island,Greece canag@ct.aegean.gr GEORGE ANASTASSOPOULOS Medical Informatics Laboratory, Medical School, Democritus University of Thrace, Alexandroupolis, 68100, Greece anasta@med.duth.gr Osteoporosis is a disease of bones that leads to an increased risk of fracture and it is characterized by low bone mineral density and micro-architectural deterioration of bone tissue. In this article, the dataset consists of 3426 subjects (1083 pathological and 2343 healthy cases) whose diagnosis was based on laboratory and osteal bone densitometry examination. In all cases, four diagnostic factors for osteoporosis risk prediction, namely age, sex, height and weight were stored for later evaluation with the selected classifiers. In order to categorize subjects into two classes (osteoporosis, non- osteoporosis), twenty machine learning techniques were assessed, based on their popularity and frequency in biomedical engineering problems. All classifiers have been evaluated using the well- known 10-fold cross validation method and the results are reported analytically. In addition, a feature selection method identified that with the use of only two diagnostic factors (age and weight), similar performance could be achieved. The scope of the proposed exhaustive methodology is to assist therapists in osteoporosis prediction, avoiding unnecessary further testing with bone densitometry. Keywords: Osteoporosis; classifiers; machine learning; feature selection. 1. Introduction Osteoporosis is the prevailing bone’s disease, and its features are low bone density mass and the modification of their micro-architecture structure, so that bones’ tolerance is reduced and the risk of fracture is increased. In osteoporosis, the Bone Mineral Density (BMD) is reduced; the bone micro-architecture is disrupted whereas the concentration and the variety of proteins in bones are altered. The classic osteoporotic fractures are hip, vertebral and wrist fractures. Osteoporotic fractures are defined as occurring at a site