Comparison between Sequential Organ Failure Assessment score (SOFA) and Cardiac Surgery Score (CASUS) for mortality prediction after cardiac surgery

Abstract

Background: Our purpose was to evaluate and compare the accuracy of the "Sequential Organ Failure Assessment" score (SOFA) and the "Cardiac Surgery Score" (CASUS) for the prediction of mortality after cardiac surgery.

Methods: Between January 1, 2007 and December 31, 2008 we prospectively included all consecutive adult patients admitted to our intensive care unit (ICU) after cardiac surgery. Both scoring systems were calculated daily from the 1st day in the ICU (day of operation) until the 7th ICU day. We evaluated the ICU mortality prediction of both models using calibration and discrimination statistics.

Results: 2801 patients (29.6% females) were included. Mean age was 66.9 ± 10.7 years. Intensive care unit mortality was 5.2%. The calibration of the "Sequential Organ Failure Assessment Score" and "Cardiac Surgery Score" was reliable for all days (p ≥ 0.05). CASUS was more accurate in predicting survival and mortality compared to SOFA for all days, as evidenced by the larger areas under the Receiver Operating Characteristic curves.

Conclusions: Both CASUS and SOFA are reliable mortality prediction tools after cardiac surgery. However, CASUS was more accurate in predicting the individual patient's risk of mortality. Thus, use of the CASUS in cardiac surgery intensive care units is recommended.