Predictive performance of an extended NEWS model for acute deterioration in general ward inpatients: a retrospective observational study

Background: This study evaluated whether an extended model combining the National Early Warning Score (NEWS) with blood lactate and serum total CO 2 improves prediction of acute deterioration in adult general ward inpatients.Methods: The study analyzed electronic medical records from 437 patients admitted to a tertiary general hospital in Ulsan Metropolitan City from January 1 to December 31, 2024.Data were extracted from electronic medical records using a literature-informed data collection form.Analyses included descriptive statistics, the chi-square test, the t-test, logistic regression, and receiver operating characteristic analysis with area under the receiver operating characteristic curve (AUROC) estimation, performed using SPSS version 24.0.Results: In the extended model, each 1-point increase in NEWS and each 1 mmol/L increase in blood lactate were associated with higher odds of unplanned intensive care unit (ICU) admission (odds ratio [OR] = 1.23 and 1.22, respectively), whereas each 1 mmol/L increase in serum total CO 2 was associated with lower odds (OR = 0.94).For 7-day mortality, NEWS and blood lactate were associated with higher odds of death (OR = 1.17 and 1.16, respectively), whereas serum total CO 2 was associated with lower odds (OR = 0.91).The AUROC increased from .69 to .74 (p = .009)for unplanned ICU admission and from .68 to .77(p = .003)for 7-day mortality.Conclusion: Adding blood lactate and serum total CO 2 to NEWS improved discrimination for unplanned ICU admission and 7-day mortality.The extended model may support clinical decision-making and timely rapid response team intervention in general ward settings.