DECAF Score Calculator — COPD Exacerbation Mortality Risk

About

The DECAF score was developed and validated by Steer et al. in 2012-2014 using a large UK-based cohort of patients admitted with AECOPD. The score was derived from the EDED study (n=920) and externally validated in the DECAF study (n=1,695). The acronym DECAF represents the five independent predictors of mortality from the derivation cohort: Dyspnea (eMRCD 5a or 5b), Eosinopenia (eosinophil count <0.05×10⁹/L), Consolidation (chest X-ray), Acidemia (arterial pH <7.35), and atrial Fibrillation (history or current). The score has demonstrated excellent discriminatory power (AUC 0.82-0.86) for in-hospital mortality and outperforms other COPD severity scores including CURB-65 and the BAP-65 score.

Formula

DECAF = Dyspnea (eMRCD 5a/b = 1 pt) + Eosinopenia (<0.05×10⁹/L = 1 pt) + Consolidation on CXR (1 pt) + Acidemia (pH 7.3-7.35 = 1 pt, pH <7.3 = 2 pts) + Atrial Fibrillation (1 pt)

The DECAF score is calculated by assigning points to five clinical parameters. Dyspnea: 1 point for eMRCD grade 5a or 5b (housebound or breathless leaving the house). Eosinopenia: 1 point for eosinophil count <0.05×10⁹/L. Consolidation: 1 point for consolidation on chest X-ray consistent with pneumonia. Acidemia: arterial pH 7.30-7.35 = 1 point, pH <7.30 = 2 points. Atrial Fibrillation: 1 point for known history or current AF on ECG. Total score ranges from 0-6. Mortality rates by score: 0 → 0.4%, 1 → 2.1%, 2 → 6.6%, 3 → 14.5%, 4 → 25.0%, 5-6 → 46.2%. The score can be used to guide admission decisions: score 0-1 may be suitable for ward-level care or supported discharge, score 2 requires inpatient care, and score 3-6 warrants consideration for HDU/ICU-level care.

Score Interpretation

Acute exacerbations of COPD are a leading cause of hospital admission worldwide, with in-hospital mortality rates of 2.5-11% in published series. Identifying patients at highest risk of death enables appropriate triage to higher levels of care and may improve outcomes. The DECAF score is unique among COPD severity scores in that it was specifically designed and validated for predicting in-hospital mortality in AECOPD. It includes key pathophysiological parameters (hypoxemia/eosinopenia reflect ongoing inflammation and impaired host response) and clinical markers of disease severity (consolidation indicates presence of pneumonia, AF reflects cardiac comorbidity and physiological stress, and eMRCD captures baseline functional status). The score's simplicity (five clinical parameters easily assessed on admission) makes it practical for frontline clinicians in emergency departments and acute medical units.

Reference Ranges