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Clinical decision making is a pervasive task that needs to be accurate. Knowledge models extracted from medical data should be novel, interesting and comprehensible to clinicians. Data mining techniques have been widely used in Computer Aided Diagnosis (CAD) systems, because of their ability to discover hidden patterns and relationships to solve the diagnostic problems in medical data (Sadoughi, Ghaderzadeh, Fein, & Standring, 2014). The common data mining tasks are association rule mining, clustering and classification (Han & Kamber, 2000). Association rule mining is a process of finding frequent patterns, associations, correlation among sets of items in transaction databases, relational databases and other information repositories. Clustering is a process of finding similarities between data according to the characteristics found in the data and grouping similar data objects into clusters. Classification is a supervised machine learning technique and is carried out in two steps namely learning and classification. In the learning step the classification model is constructed. In the classification step the constructed model is used to classify the test samples.
To address the problem of classification, the commonly used approaches are Artificial Neural Network (ANN), Decision trees, Support Vector Machine (SVM), Bayesian classifiers and K-Nearest Neighbor classifiers (Neelamegam & Ramaraj, 2013). Researchers have also developed hybrid classifiers to address the classification problem in clinical datasets and microarray gene expression data. A hybrid classifier for classifying leukemia gene expression data is presented in (Susmi, Nehemiah, Kannan, & Christopher, 2015). Mokeddem and Baghdad, (2016) performed an assessment for predicting coronary heart disease using fuzzy logic based clinical decision support system. Dasarathy and Sheela, (1979) introduced an ensemble based classification system. This system partitions the feature space into two or more classifiers. In 1990, Hansen and Salamon proved the generalization performance of a neural network that can be improved using an ensemble based neural network.
ANNs are computational models inspired by the biological nervous system (De Castro, 2006). Radial Basis Function (RBF) network is a feedforward ANN introduced by Broomhead and Lowe (Broomhead & Lowe, 1988). RBF network has several advantages when compared to the other types of ANNs, such as their simple structure, good approximation capabilities and faster learning rate (Qasem, Shamsuddin, Hashim, Darus, & Al-Shammari, 2013). Because of the above capabilities, the RBFNN can be applied in many science and engineering domains, such as function approximation, time series prediction, curve fitting, control and classification problems (Devaraj, Yegnanarayana, & Ramar, 2002; Du & Zhai, 2008; Fu & Wang, 2003; Han & Xi, 2004; Oyang, Hwang, Ou, Chen, & Chen, 2005).