Comparison of two scores for short-term outcomes in patients with COPD exacerbation in the emergency department: the Ottawa COPD Risk Scale and the DECAF score

Abstract

Background While clinical decision rules have been developed to evaluate exacerbations and decisions on hospitalisation and discharge in emergency departments (EDs) in patients with chronic obstructive pulmonary disease (COPD), these rules are not widely used in EDs. In this study, we compare the predictive efficacy of the Ottawa Chronic Obstructive Pulmonary Disease Risk Scale (OCRS) and the Dyspnea, Eosinopenia, Consolidation, Acidemia, and Atrial Fibrillation (DECAF) score in estimating the short-term poor outcome of patients in our ED with exacerbations of COPD. Methods This single-centre prospective observational study was conducted over 6 months. Patients with acute exacerbations of COPD admitted to the ED during the study period were included in the study. A poor outcome was defined as any of the following: readmission and requiring hospitalisation within 14 days of discharge, requiring mechanical ventilation on the first admission, hospitalisation for longer than 14 days on the first admission, or death within 30 days. The sensitivity and specificity of the OCRS and the DECAF score for a poor outcome and for mortality were calculated. Results Of the 385 patients who participated in the study, 85 were excluded based on the exclusion criteria. 66% of the patients were male, and the mean age was 70.15±10.36 years. A total of 20.7% of all patients (n=62) experienced poor outcomes. The sensitivity of an OCRS score <1 for predicting a poor outcome in patients was 96.8% (95% CI 88.8–99.6%) and the specificity was 18.5% (95% CI 13.8–24.0%). The sensitivity and specificity of an OCRS score <2 were 83.3% (95% CI 35.9–99.6%) and 65.5% (95% CI 59.6–70.7%), respectively. The sensitivity and specificity of a DECAF score <1 were 88.7% (95% CI 78.1–95.3%) and 34.5% (95% CI 28.4–40.9%), respectively. When the DECAF score was <2, sensitivity and specificity were 69.3% (95% CI 56.4–80.4%) and 74.8% (95% CI 68.8–80.2%), respectively. Conclusion Our physicians achieved high specificity but low sensitivity in predicting a poor outcome. The OCRS is the more sensitive of the two tools, while the DECAF score is more specific in predicting a poor outcome when all threshold values are evaluated. While both tools may results in unnecessary hospitalisation, they can reduce the incidence of hospital discharge of patients with exacerbations of COPD who will develop poor outcomes in the ED.