  In this study we propose a novel method to successfully detect the ADRs using
feature matrix and feature selection. A feature matrix, which characterizes the
medical events before patients take drugs or after patients take drugs, is
created from THIN database. The feature selection method of Student's t-test is
used to detect the significant features from thousands of medical events. The
significant ADRs, which are corresponding to significant features, are
detected. Experiments are performed on the drug Pioglitazone. Compared to other
computerized methods, our proposed method achieves good performance.
