Performance of the National Early Warning Score 2 for diagnosing bacterial sepsis: a prospective single-center study in Vietnam

Abstract

Background: Early recognition of sepsis is vital for enhancing patient outcomes. While the National Early Warning Score 2 (NEWS2) has demonstrated good performance for identifying sepsis in emergency departments, its diagnostic accuracy in other clinical environments remains uncertain. This study aimed to evaluate the diagnostic accuracy of NEWS2 for bacterial sepsis at an infectious diseases department.

Methods: This prospective diagnostic accuracy study consecutively enrolled adult patients admitted to the Department of Infectious Diseases (DID), Military Hospital 175, Vietnam, between March and July 2025. Eligible patients were aged ≥18 years and had suspected bacterial infection. NEWS2 was assessed within the first 24 hours of hospitalization. For patients admitted from the Emergency Department, NEWS2 was calculated using the initial clinical data recorded there; for those admitted from the Outpatient Clinic, it was assessed on admission to the DID. Sepsis was defined according to Sepsis-3 criteria. Diagnostic performance was evaluated using the area under the receiver operating characteristic curve (AUROC), sensitivity, and specificity.

Results: Of 741 patients screened, 120 were included in the final analysis, 83 patients (69.2%) were diagnosed with sepsis, including 1 case of septic shock. NEWS2 demonstrated moderate discrimination for identifying sepsis, with an AUROC of 0.75 (95% confidence interval: 0.66–0.84). The optimal cut-off was ≥5, yielding a sensitivity of 71.1% and a specificity of 73.0%.

Conclusions: NEWS2 demonstrated moderate diagnostic performance for identifying sepsis in this setting and may serve as a useful adjunctive tool for early risk stratification, particularly in resource-limited infectious diseases departments.