Comparison of severity scoring systems A-DROP and CURB-65 for community-acquired pneumonia

Background and objective: The initial assessment of the severity of community-acquired pneumonia (CAP) is important for patient management. The Japanese Respiratory Society (JRS) has proposed a 6-point scale (0-5) to assess the clinical severity of CAP. The A-DROP scoring system assesses the following parameters: (i) Age (male ≥ 70 years, female ≥ 75 years); (ii) Dehydration (blood urea nitrogen (BUN) ≥ 210 mg/L); (iii) Respiratory failure (SaO ₂ ≤ 90% or PaO₂ ≤ 60 mm Hg); (iv) Orientation disturbance (confusion); and (v) low blood Pressure (systolic blood pressure ≤ 90 mm Hg). A-DROP is a modified version of CURB-65 (confusion, BUN > 7 mmol/L (200 mg/L), respiratory rate ≥ 30/min, low blood pressure (diastolic ≤ 60 mm Hg or systolic < 90 mm Hg, and age ≥ 65 years) proposed by the British Thoracic Society. However, validation of A-DROP has not been attempted nor has it been compared with CURB-65. The aim of this study was to confirm that A-DROP is equivalent to CURB-65 for predicting severity of CAP. Methods: A retrospective observational study was conducted of patients with CAP hospitalized at a single centre between November 2005 and January 2007. The 30-day mortality after admission was compared following assessment of severity using the A-DROP and CURB-65 scoring systems. Results: Three-hundred and twenty-nine patients were evaluated. The areas under the receiver operating characteristic curves were 0.846 (95% confidence interval (CI): 0.790-0.903) and 0.835 (95% CI: 0.763-0.908) for A-DROP and CURB-65, respectively. Conclusion: The JRS A-DROP can be used to assess severity of CAP, and gives similar results to CURB-65.