Severity stratification scores developed in Intensive Care Units (ICUs) are used in interventional studies to identify the most critically ill. Studies that evaluate accuracy of these scores in ICU patients admitted with pneumonia are lacking. This study aims to determine performance of severity scores as predictors of mortality in critically ill patients admitted with pneumonia.
Prospective cohort study in a general ICU in Brazil. ICU severity scores (SAPS 3 and qSOFA), prognostic scores of pneumonia (CURB-65 and CRB-65), clinical and epidemiological variables in the first 6 hours of hospitalization were analyzed.
A total of 200 patients were included between August 2015 and July 2018 with a median age of 81 years (IQR 67-90) and female predominance (52%) primarily admitted from the emergency department (65%) with community acquired pneumonia (80.5%). Poor discriminative performance in predicting mortality was found with SAPS 3, CURB-65, CRB-65 and qSOFA. Multivariate regression identified variables independently associated with mortality that were used to develop a novel pneumonia specific ICU severity score (Pneumonia SHOCK score) that outperformed SAPS3, CURB-65 and CRB-65 (AUC 0.80 vs 0.74, 0.65 and 0.63, respectively). Discriminate function of the Pneumonia SHOCK score was validated in an external multi-center cohort of critically ill patients admitted with community acquired pneumonia (AUC 0.81).
We created a parsimonious score system that accurately identifies elderly and non-elderly patients with pneumonia at highest risk of ICU death. These findings are critical to accurately stratify patients with severe pneumonia in therapeutic trials that aim to reduce pneumonia mortality.

© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: