Predictors of outcomes in emergency department patients with suspected infections and without fulfillment of the sepsis criteria.

Background: Data on patient characteristics and determinants of serious outcomes for acutely admitted patients with infections who do not fulfill the sepsis criteria are sparse. The study aimed to characterize acutely admitted emergency department (ED) patients with infections and a composite outcome of in-hospital mortality or transfer to the intensive care unit without fulfilling the criteria for sepsis and to examine predictors of the composite outcome.

Methods: This was a secondary analysis of data from a prospective observational study of patients with suspected bacterial infection admitted to the ED between October 1, 2017 and March 31, 2018. A National Early Warning Score 2 (NEWS2) ≥ 5 within the first 4 h in the ED was assumed to represent a sepsis-like condition with a high risk for the composite endpoint. Patients who achieved the composite outcome were grouped according to fulfillment of the NEWS2 ≥ 5 criteria. We used logistic regression analysis to estimate the unadjusted and adjusted odds ratio (OR) for the composite endpoint among patients with either NEWS2  < 5 (NEWS2-) or NEWS2  ≥ 5 (NEWS2+).

Results: A total of 2055 patients with a median age of 73 years were included. Of these, 198 (9.6%) achieved the composite endpoint, including 59 (29.8%) NEWS2- and 139 (70.2%) NEWS2+ patients, respectively. Diabetes (OR 2.23;1.23-4.0), a Sequential Organ Failure Assessment (SOFA) score ≥ 2 (OR 2.57;1.37-4.79), and a Do-not-attempt-cardiopulmonary-resuscitation order (DNACPR) on admission (OR 3.70;1.75-7.79) were independent predictive variables for the composite endpoint in NEWS2- patients (goodness-of-fit test P = 0.291; area under the receiver operating characteristic curve for the model (AUROC) = 0.72). The regression model for NEWS2+ patients revealed that a SOFA score ≥ 2 (OR 2.79; 1.59-4.91), hypothermia (OR 2.48;1.30-4.75), and DNACPR order on admission were predictive variables for the composite endpoint (goodness-of-fit test P = 0.62; AUROC for the model = 0.70).

Conclusion: Approximately one-third of the patients with infections and serious outcomes during hospitalization did not meet the NEWS2 threshold for likely sepsis. Our study identified factors with independent predictive values for the development of serious outcomes that should be tested in future prediction models.