Date Published: January 25, 2019
Publisher: Public Library of Science
Author(s): Anniek Brink, Jelmer Alsma, Rob Johannes Carel Gerardus Verdonschot, Pleunie Petronella Marie Rood, Robert Zietse, Hester Floor Lingsma, Stephanie Catherine Elisabeth Schuit, Juan Carlos Lopez-Delgado.
In hospitalized patients, the risk of sepsis-related mortality can be assessed using the quick Sepsis-related Organ Failure Assessment (qSOFA). Currently, different tools that predict deterioration such as the National Early Warning Score (NEWS) have been introduced in clinical practice in Emergency Departments (ED) worldwide. It remains ambiguous which screening tool for mortality at the ED is best. The objective of this study was to evaluate the predictive performance for mortality of two sepsis-based scores (i.e. qSOFA and Systemic Inflammatory Response Syndrome (SIRS)-criteria) compared to the more general NEWS score, in patients with suspected infection directly at presentation to the ED.
We performed a retrospective cohort study. Patients who presented to the ED between June 2012 and May 2016 with suspected sepsis in a large tertiary care center were included. Suspected sepsis was defined as initiation of intravenous antibiotics and/or collection of any culture in the ED. Outcome was defined as 10-day and 30-day mortality after ED presentation. Predictive performance was expressed as discrimination (AUC) and calibration using Hosmer-Lemeshow goodness-of-fit test. Subsequently, sensitivity, and specificity were calculated.
In total 8,204 patients were included of whom 286 (3.5%) died within ten days and 490 (6.0%) within 30 days after presentation. NEWS had the best performance, followed by qSOFA and SIRS (10-day AUC: 0.837, 0.744, 0.646, 30-day AUC: 0.779, 0.697, 0.631). qSOFA (≥2) lacked a high sensitivity versus SIRS (≥2) and NEWS (≥7) (28.5%, 77.2%, 68.0%), whilst entailing highest specificity versus NEWS and SIRS (93.7%, 66.5%, 37.6%).
NEWS is more accurate in predicting 10- and 30-day mortality than qSOFA and SIRS in patients presenting to the ED with suspected sepsis.
Sepsis is a syndrome characterised by both signs of infection and manifestations of a systemic host response . Sepsis is the primary cause of mortality from infection. The definition of sepsis has changed throughout the last decades. In February 2016 the Third International Consensus Definition for Sepsis (Sepsis-3) replaced the Sepsis-2 definition dating from 2001 [1–3]. Sepsis is currently defined as a “life-threatening organ dysfunction caused by a dysregulated host response to infection”, in which organ dysfunction is represented by an increase of at least two points in the Sequential Organ Failure Assessment (SOFA) score . The Systemic Inflammatory Response Syndrome (SIRS) score, which was part of the definition in Sepsis-1 and -2, has been abandoned.
In this retrospective observational study of patients visiting the ED with a suspected sepsis we found that NEWS was superior to qSOFA and SIRS in predicting 10- and 30-day mortality for both discrimination and calibration. The different prompts all have different sensitivities and specificities for mortality. qSOFA has the highest specificity and lowest sensitivity, SIRS has the lowest specificity and highest sensitivity. NEWS has both an intermediate sensitivity and specificity, but is the best overall predictor in distinguishing high risk from low risk patients. NEWS has a lower sensitivity resulting in a significant number of false negatives, i.e. not all the patients who eventually died were identified with NEWS. NEWS was the only model with a good agreement between the expected and observed outcomes, i.e. calibration. However, none of the prediction models succeeded to fulfil all performance assessments, which would ideally be the case. Subsequent measurements of NEWS (e.g. hourly) will potentially identify patients who deteriorate during the stay in the ED and may improve sensitivity. We conclude that at presentation to the ED NEWS can be used as an alternative screening tool for patients with suspected sepsis who are at risk for deterioration, multi-organ failure, and subsequently death.
In conclusion, the NEWS is more accurate in predicting 10- and 30-day mortality than qSOFA and SIRS in patients suspected of sepsis on initial presentation to the ED. Our finding suggests that the introduction of the NEWS in the ED with subsequent measurements should be further studied. This will potentially aid the early detection of all patients at risk for deterioration in the ED including those at risk of sepsis-related mortality.