Background Despite exacerbations of chronic obstructive pulmonary disease (COPD) being both common and often fatal, accurate prognostication of patients hospitalised with an exacerbation is difficult. For exacerbations complicated by pneumonia, the CURB-65 prognostic tool is frequently used but its use in this population is suboptimal.

Methods Consecutive patients hospitalised with an exacerbation of COPD were recruited. Admission clinical data and inhospital death rates were recorded. Independent predictors of outcome were identified by logistic regression analysis and incorporated into a clinical prediction tool.

Results 920 patients were recruited: mean (SD) age was 73.1 (10.0) years; 53.9% were female subjects; mean (SD) forced expiratory volume in one second was 43.6 (17.2) % predicted; and 96 patients (10.4%) died in hospital. The five strongest predictors of mortality (extended MRC Dyspnoea Score, eosinopenia, consolidation, acidaemia, and atrial fibrillation) were combined to form the Dyspnoea, Eosinopenia, Consolidation, Acidaemia and atrial Fibrillation (DECAF) Score. The Score, which underwent internal bootstrap validation, showed excellent discrimination for mortality (area under the receiver operator characteristic curve =0.86, 95% CI 0.82 to 0.89) and performed more strongly than other clinical prediction tools. In the subgroup of patients with coexistent pneumonia (n=299), DECAF was a significantly stronger predictor of mortality than CURB-65.

Conclusions The DECAF Score is a simple yet effective predictor of mortality in patients hospitalised with an exacerbation of COPD and has the potential to help clinicians more accurately predict prognosis, and triage place and level of care to improve outcome in this common condition.