Benchmarking Feature Selection Methods with Different Prediction Models on Large-Scale Healthcare Event Data

With the development of the Electronic Health Record (EHR) technique, vast volumes of digital clinical data are generated. Based on the data, many methods are developed to improve the performance of clinical predictions. Among those methods, Deep Neural Networks (DNN) have been proven outstanding with respect to accuracy by employing many patient instances and events (features). However, each patient-specific event requires time and money. Collecting too many features before making a decision is insufferable, especially for time-critical tasks such as mortality prediction. So it is essential to predict with high accuracy using as minimal clinical events as possible, which makes feature selection a critical question. This paper presents detailed benchmarking results of various feature selection methods, applying different classification and regression algorithms for clinical prediction tasks, including mortality prediction, length of stay prediction, and ICD-9 code group prediction. We use the publicly available dataset, Medical Information Mart for Intensive Care III (MIMIC-III), in our experiments. Our results show that Genetic Algorithm (GA) based methods perform well with only a few features and outperform others. Besides, for the mortality prediction task, the feature subset selected by GA for one classifier can also be used to others while achieving good performance.