Prognostic accuracy of CURB-65, serum lactate, and a combined model for predicting intensive care unit admission and in-hospital mortality in emergency department patients with pneumonia: a retrospective cohort study
Suphi Bahadirli, Mustafa Sefa Isin, Mehmet Berke Isler, Ayse Gulnihan Simsek, Nur Muhammed Cinar, Sebnem Zeynep Eke KurtBackground:
Community-acquired pneumonia is a leading cause of emergency department (ED) presentation, hospitalization, and in-hospital mortality. CURB-65 is the most widely used bedside risk stratification tool; however, it does not capture tissue hypoperfusion. We evaluated the combined discriminative performance of CURB-65 and admission serum lactate for predicting intensive care unit (ICU) admission and in-hospital mortality.
Methods:
This was a retrospective, single-center cohort study conducted at a university hospital ED (January 2023–July 2025). After excluding patients with missing lactate (n = 204), incomplete CURB-65 components (n = 307), or other reasons (n = 36), a total of 317 out of 864 consecutive patients with pneumonia were included. Predictors were assessed using binary logistic regression; the area under the curve (AUC) were compared using the DeLong method. Calibration was assessed with the Hosmer–Lemeshow test; internal validation used bootstrap resampling (1000 iterations).
Results:
Median age was 70 years (interquartile range: 57–80); 47.9% were female. ICU admission occurred in 60 patients (18.9%), and in-hospital mortality occurred in 25 (7.9%). Both CURB-65 (odds ratio: 2.48; 95% confidence interval: 1.75–3.50;
Conclusion:
Adding serum lactate to CURB-65 significantly improved discriminative performance for ICU admission and in-hospital mortality in ED pneumonia patients. The high negative predictive value supports its utility for ruling out adverse outcomes in low-risk patients.