Evaluating ICU Clinical Severity Scoring Systems and Machine Learning Applications: APACHE IV/IVa Case Study

Clinical scoring systems have been developed for many specific applications, yet they remain underutilized for common reasons such as model inaccuracy and difficulty of use. For intensive care units specifically, the Acute Physiology and Chronic Health Evaluation (APACHE) score is used as a decision-making tool and hospital efficacy measure. In an attempt to alleviate the general underlying limitations of scoring instruments and demonstrate the utility of readily available medical databases, machine learning techniques were used to evaluate APACHE IV and IVa prediction measures in an open-source, teleICU research database. The teleICU database allowed for large-scale evaluation of APACHE IV and IVa predictions by comparing predicted values to the actual, recorded patient outcomes along with preliminary exploration of new predictive models for patient mortality and length of stay in both the hospital and the ICU. An increase in performance was observed in the newly developed models trained on the APACHE input variables highlighting avenues of future research and illustrating the utility of teleICU databases for model development and evaluation.