Validation of prognostic accuracy of the SOFA score, SIRS criteria, and qSOFA score for in-hospital mortality among cardiac-, thoracic-, and vascular-surgery patients admitted to a cardiothoracic intensive care unit.

Abstract

The sepsis-3 criteria have emphasized the value of a change of two or more points on the SOFA, introduced the qSOFA, and removed the systemic inflammatory response syndrome (SIRS) criteria from the sepsis definition. To externally validate and assess the discriminatory capacities of an increase in the SOFA score by two or more points, the presence of two or more SIRS criteria, or a qSOFA score of 2 or more points for outcomes in 5109 patients, the vast majority of whom were postcardiac surgery patients who were admitted to a Cardiothoracic Surgical ICU in Singapore. A retrospective cohort analysis of 5109 patients with an infection-related primary admission diagnosis in the cardiothoracic intensive care unit (CTICU) at the National University Hospital (NUH) in Singapore from 2010 to 2016. The SOFA, qSOFA, and SIRS criteria were applied to the data representing the worst condition within 24 hours of ICU admission. The primary outcome was in-hospital mortality. Discrimination was assessed using the area under the receiver operating characteristic curve (AUROC). In 5109 patients, the average mortality of patients with an increase in the SOFA scores of less than 2 points was 3.5% (n = 64), and it was 6% (n = 199) for those with an increase in the SOFA scores of 2 or more points. The mortality of patients with an increase in the qSOFA scores of less than 2 points was 2.6% (n = 7), and it was 5.3% (n = 256) for those with an increase in the qSOFA scores of 2 or more points. The mortality of patients with an increase in the SIRS criteria of less than 2 points was 3.6% (n = 30), and it was 5.4% (n = 233) for those with an increase in the SIRS criteria of 2 or more points. The AUROC of in-hospital mortality of patients with an increase in the SOFA, qSOFA, and SIRS criteria of 2 or more points was 0.96, 0.95, and 0.95, respectively. In adults with suspected infection admitted to the CTICU in NUH, the change in in-hospital mortality between patients with an increase in SOFA scores of less than 2 and those with an increase of 2 or more was 2.5 percentage points. In contrast to other studies, the absolute change in mortality was nearly the same compared to the qSOFA and SIRS criteria, and the qSOFA score had the greatest percentage increase of 104%, compared to 71% for the SOFA score and 50% for the SIRS criteria. Besides, from the perspective of discriminatory capacities, an increase in SOFA scores of 2 or more did not demonstrate significantly greater prognostic accuracy for in-hospital mortality than equivalent increases in qSOFA scores or SIRS criteria. These findings suggest distinctive characteristics of the study population in the CTICU that are different from the general population.