Validation of NEWS2, SIRS, and qSOFA in Postoperative Cardiac Patients: A Retrospective Cohort Study

Abstract

IntroductionThe ‘quick Sepsis Related Organ Failure Assessment’ (qSOFA), ‘Systemic Inflammatory Response Syndrome’ (SIRS), and ‘National Early Warning Score’ 2 (NEWS2) scores are yet to be comparatively validated in ward-based cardiac surgical patients despite widespread routine use in clinical practice. We sought to assess the predictive validity of NEWS, SIRS, and qSOFA in identifying postoperative, ward-level cardiac surgical patients at risk of poor short-term mortality. MethodsAll adult patients who underwent cardiac surgery at a single tertiary center between November 2014 and October 2017 were identified. Data for bedside observations, hematological results, and microbiology requests were obtained from electronic health records. Survival data were acquired from a national registry. The primary outcome was the discriminatory ability, measured by the area under the receiver operating characteristic (AUROC), of each score for in-hospital mortality. ResultsOne thousand five hundred forty three (male n = 1101, 71%) patients were included. Overall in-hospital mortality was 2.4%. There was no significant difference in discriminatory ability of NEWS (AUROC 0.5060), SIRS (AUROC 0.4874), and qSOFA (AUROC 0.5139) for in-hospital mortality (P = 0.881). Sensitivity for this outcome was ubiquitously low (13.51-40.54%). ConclusionsCurrent illness-severity scores show a low discriminatory ability for in-hospital mortality in ward-based cardiac surgical patients. Caution should be used in the application of these prognostic screening tools for early detection of poor outcomes in this population.