Predicting mortality in patients with community-acquired pneumonia and low CURB-65 scores

Some patients classified as having non-severe community-acquired pneumonia (CAP) by CURB-65 subsequently die. The objective of this study was to identify risk factors for mortality in non-severe patients and to test how risk factors might be used. Patients who had a CURB-65 score of 0-2 on admission to hospital and were alive at 30 days were compared with those who died. Identified risk factors were included in new variations of CURB-65 and new management strategies. Age >65 years, blood urea >7 mmol/l, bilateral/multi-lobar appearance of the chest radiograph (CXR), social situation (living alone/no fixed abode or residential/nursing care) and temperature <36 degrees C were associated with mortality (p < 0.05). A two-step approach, with initial use of CURB-65 followed by the above non-CURB-65 criteria, increased the proportion of patients correctly classified as having severe CAP who subsequently died from 54/76 (71%, 95% confidence interval [CI] 61% to 81%) to 72/76 (95%, 95% CI 90% to 100%). The consideration of additional risk factors in a two-step approach can improve the stratification of mortality by CURB-65. Physicians should be cautious about managing patients with CAP as outpatients if they have a CURB-65 score of 1 (or more) and have at least one of the three additional risk factors identified.