Prognostic factors for mortality due to pneumonia among adults from different age groups in Singapore and mortality predictions based on PSI and CURB-65.

INTRODUCTION Pneumonia is associated with considerable mortality. However, there is limited information on age-specific prognostic factors for death from pneumonia. METHODS Patients hospitalised with a diagnosis of pneumonia through the emergency department were stratified into three age groups: 18-64 years, 65-84 years and >= 85 years. Multivariate logistic regression and receiver operating characteristic curve analyses were conducted to evaluate prognostic factors for mortality and the performance of pneumonia severity scoring tools for mortality prediction. RESULTS A total of 1,902 patients were enrolled (18-64 years: 614 [32.3%]; 65-84 years: 944 [49.6%]; >= 85 years: 344 [18.1%]). Mortality rates increased with age (18-64 years: 7.3%; 65-84 years: 16.1%; >= 85 years: 29.7%; p < 0.001). Malignancy and tachycardia were prognostic of mortality among patients aged 18-64 years. Male gender, malignancy, congestive heart failure and eight other parameters reflecting acute disease severity were associated with mortality among patients aged 65-84 years. For patients aged >= 85 years, altered mental status, tachycardia, blood urea nitrogen, hypoxaemia, arterial pH and pleural effusion were significantly predictive of mortality. The Pneumonia Severity Index (PSI) was more sensitive than CURB-65 (confusion, uraemia, respiratory rate >= 30 per minute, low blood pressure, age >= 65 years) for mortality prediction across all age groups. CONCLUSION The predictive effect of prognostic factors for mortality varied among patients with pneumonia from the different age groups. PSI performed significantly better than CURB-65 for mortality prediction, but its discriminative power decreased with advancing age.