The Effectiveness of Geriatric Pneumonia Severity Index in Predicting Mortality

Background: Pneumonia severity index (PSI) estimates the risk of 30-day mortality in patients with pneumonia. In this study, we aim to develop a simplified version of the PSI (G-PSI) to estimate the risk of mortality in geriatric patients with community-acquired pneumonia (CAP). Methods: This retrospective study included 186 patients aged 65 and older with a diagnosis of CAP. PSI score and 30-day mortality rate of each patient were calculated. PSI parameters were analyzed using univariate regression analysis and the G-PSI scoring system was established to predict 30-day mortality and compared with PSI. Results: Significant effectiveness of the values of cancer (odds ratio (OR) = 3.67; 95% confidence interval (CI): 1.42-9.48), altered mental status (OR = 0.79; 95% CI: 0.68-0.92), systolic blood pressure (OR = 0.98; 95% CI: 0.97-1.00), haematocrit (Hct) (OR = 0.87; 95% CI: 0.81-0.93) and blood urea nitrogen (BUN) (OR = 1.04; 95% CI: 1.02-1.06) were observed for predicting mortality in univariate regression analysis. G-PSI scoring system, like PSI score (if cancer + 30 points, if altered mental status +20 points, if systolic blood pressure ＜ 90mmHg+ 20 points, if Hct ＜ 30% + 10 points and if BUN ≥ 30 mg/dl + 30 points) was created. The area under the receiver operating characteristic curve (AUC)was 0.762 (95% CI 0.673-0.851), revealing the excellent discriminatory ability of the G-PSI model. The AUC for the PSI score was 0.719 (95% CI 0.631-0.806).When G-PSI and PSI were compared, G-PSI had a high level of significance in predicting 30-day mortality. Conclusion: Calculated with only five parameters from standard PSI information, G-PSI accurately displays the 30-day mortality risk of geriatric patients with CAP. The applicability of the G-PSI is easier in a busy emergency service environment with similar prognostic accuracy and clinical prediction.