The Pros and Cons of the Prediction Game: The Never-ending Debate of Mortality in the Intensive Care Unit

Background: The Simplified Acute Physiology Score (SAPS) II, Acute Physiology and Chronic Health Evaluation (APACHE) II, and Sequential Organ Failure Assessment (SOFA) scales are scoring systems used in intensive care units (ICUs) worldwide. We aimed to investigate their usefulness in predicting short- and long-term prognosis in the local ICU. Methods: This single-center observational study covered 905 patients admitted from 1 January 2015 to 31 December 2017 to a tertiary mixed ICU. SAPS II, APACHE II, and SOFA scores were calculated based on the worst values from the first 24 h post-admission. Patients were divided into surgical (SP) and nonsurgical (NSP) subjects. Unadjusted ICU and post-ICU discharge mortality rates were considered the outcomes. Results: Baseline SAPS II, APACHE II, and SOFA scores were 41.1 ± 20.34, 14.07 ± 8.73, and 6.33 ± 4.12 points, respectively. All scores were significantly lower among SP compared to NSP (p < 0.05). ICU mortality reached 35.4% and was significantly lower for SP (25.3%) than NSP (57.9%) (p < 0.001). The areas under the receiver-operating characteristic (ROC) curves were 0.826, 0.836, and 0.788 for SAPS II, APACHE II, and SOFA scales, respectively, for predicting ICU prognosis, and 0.708, 0.709, and 0.661 for SAPS II, APACHE II, and SOFA, respectively, for post-ICU prognosis. Conclusions: Although APACHE II and SAPS II are good predictors of ICU mortality, they failed to predict survival after discharge. Surgical patients had a better prognosis than medical ICU patients.