Proposal of improvement in patients with urinary tract infection in emergency department: Adding HCO 3 − to quick sepsis‐related organ failure assessment (qSOFA) with a cut‐off value of 1

Background: In 2016, the Sepsis‐3 Task Force introduced a simpler algorithm, named quick sepsis‐related organ failure assessment, for patients in a non‐intensive care unit setting. Objectives: The study was designed to investigate the predictive performance of quick sepsis‐related organ failure assessment for intensive care unit admission using the area under the curve of receiver operating characteristic specifically in patients of clinically diagnosed urinary tract infection in the emergency department and to compare its performance with that of systemic inflammatory response syndrome and sequential (sepsis‐related) organ failure assessment. Methods: Retrospective analyses on adult urinary tract infection patients presenting to the emergency department between June 2015 and May 2016 were undertaken. We compared patients who were admitted to the intensive care unit to those who were not. Results: Of the total 220 urinary tract infection patients, 20 (9.1%) were hospitalized to the intensive care unit and there was no in‐hospital mortality. Independent predictors for intensive care unit admission using multiple logistic regression were HCO 3 − and creatinine. The area under the curve of receiver operating characteristic values of systemic inflammatory response syndrome, quick sepsis‐related organ failure assessment, and sequential (sepsis‐related) organ failure assessment were 0.759, 0.752, and 0.824 on intensive care unit admission, respectively, and there was no significant difference between any of them. Interestingly, adding HCO 3 − to quick sepsis‐related organ failure assessment improved the predictive performance compared to quick sepsis‐related organ failure assessment alone (AUC: 0.844 vs 0.752, respectively; p  < 0.05), and a cut‐off value of 20 mmol/L for HCO 3 − yielded the largest area under the curve of receiver operating characteristic value. Moreover, when lowering the cut‐off value of quick sepsis‐related organ failure assessment to 1 and combining to HCO 3 − , its sensitivity was increased from 22% to 90%. Conclusion: Among patients presenting to the emergency department with clinically diagnosed urinary tract infection, the use of a new model, which is adding HCO 3 − to quick sepsis‐related organ failure assessment with a lowered cut‐off value of 1, resulted in greater predictive performance regarding intensive care unit admission than original quick sepsis‐related organ failure assessment.