DECAF score (COPD exacerbation)
In-hospital mortality risk in patients admitted with an acute exacerbation of COPD
Sources last checked: 2026-10-13
DECAF score (COPD exacerbation)
In-hospital mortality risk in patients admitted with an acute exacerbation of COPD
Score dyspnoea on a typical stable day in the 3 months before admission, not on arrival. In the validation study, patients with SpO₂ > 92 % on air in whom no blood gas was taken scored 0 for acidaemia.
Interpretation
| 0–1 — low risk | In-hospital mortality 1.4 % (derivation) and 1.0 % (validation). The DECAF authors describe this group as potentially suitable for hospital-at-home or early supported discharge. |
|---|---|
| 2 — intermediate risk | In-hospital mortality 8.4 % (derivation) and 5.4 % (validation). The score does not assign a site of care in this category. |
| 3–6 — high risk | In-hospital mortality 34.7 % (derivation) and 21.4 % (validation). The DECAF authors describe this group as one in which early escalation planning or, where appropriate, early palliative care is relevant. |
What is the DECAF score (COPD exacerbation)?
DECAF predicts in-hospital death in patients admitted with an acute exacerbation of COPD from five indices available at admission: Dyspnoea (extended MRC grade), Eosinopenia, Consolidation, Acidaemia and atrial Fibrillation. Steer, Gibson and Bourke derived it in two UK hospitals, and it was later validated in 1725 patients from six UK hospitals.
When to use it
- On admission with an acute exacerbation of COPD
- Identifying low-risk patients (DECAF 0–1) for hospital-at-home or early supported discharge
- Flagging high-risk patients (DECAF 3–6) for early escalation or ceiling-of-care discussions
- Pneumonic exacerbations of COPD, where CURB-65 underestimates risk
When not to use it
- Patients without an established diagnosis of COPD
- Community-acquired pneumonia without COPD — use CURB-65
- Outpatient exacerbations not requiring admission (not the derivation population)
How it is calculated
| Criterion | Points |
|---|---|
| Dyspnoea on a stable day in the previous 3 months (eMRCD) | |
| eMRCD 1–4: can leave the house unassisted | 0 |
| eMRCD 5a: too breathless to leave the house unassisted, independent in washing and/or dressing | 1 |
| eMRCD 5b: too breathless to leave the house unassisted and needs help with washing and dressing | 2 |
| Eosinopenia (eosinophils < 0.05 × 10⁹/L) | +1 |
| Consolidation on chest X-ray | +1 |
| Acidaemia (arterial pH < 7.30) | +1 |
| Atrial fibrillation (including paroxysmal AF history) | +1 |
Clinical pearls and limitations
- Score dyspnoea on a typical stable day in the 3 months before admission, not on arrival. In the validation study, patients with SpO₂ > 92 % on air in whom no blood gas was taken scored 0 for acidaemia.
- Grade dyspnoea on a typical stable day in the 3 months before admission — breathlessness on arrival overstates the score.
- The decisive distinction is between eMRCD 4 (can leave the house unassisted) and 5a/5b (cannot); simple walking aids do not count as assistance.
- Acidaemia means arterial pH < 7.30; pH 7.30–7.34 scores 0.
- In the validation study a high-risk score was also linked to a short time to death.
Frequently asked questions
What does a DECAF score of 3 mean?
It is in the high-risk group (3–6), which had in-hospital mortality of 34.7 % in the derivation cohort and 21.4 % in the validation cohort.
Is DECAF better than CURB-65 in COPD?
In the UK validation study DECAF discriminated in-hospital mortality better than CURB-65, and low-risk CURB-65 scores were falsely reassuring in pneumonic exacerbations.
What is eMRCD 5a versus 5b?
Both describe patients too breathless to leave the house unassisted. 5a patients manage washing and/or dressing themselves; 5b patients need help with both.
Do I need a blood gas for DECAF?
In the validation study, patients with SpO₂ > 92 % on room air in whom a blood gas was not taken were scored 0 for acidaemia.
Evidence and guidelines
- Primary source: Steer J, Gibson J, Bourke SC. The DECAF Score: predicting hospital mortality in exacerbations of chronic obstructive pulmonary disease. Thorax 2012;67(11):970-976.
- Echevarria C, Steer J, Heslop-Marshall K, et al. Validation of the DECAF score to predict hospital mortality in acute exacerbations of COPD. Thorax 2016;71(2):133-140 (six UK hospitals, n = 1725; source of the band mortality figures).
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