COPD Assessment Test (CAT) Calculator

questionnaire

Cough

Phlegm (mucus)

Chest tightness

Breathlessness walking up hill or stairs

Activity limitation at home

Confidence leaving home

Sleep quality

Energy levels

✓ when to use

Use in all patients with COPD at diagnosis, at each routine review, and to monitor treatment response. CAT ≥10 defines 'more symptoms' in GOLD classification. A ≥2-point change is considered clinically meaningful. More comprehensive than mMRC as it captures cough, phlegm, sleep, and energy in addition to breathlessness.

✗ when not to use

CAT is specific to COPD — not validated as a general respiratory symptom tool. Scores may be elevated by comorbidities (depression, heart failure, obesity) that contribute to similar symptoms. Not validated in acute exacerbations for guiding acute management decisions.

clinical pearls

CAT ≥10 = GOLD 'more symptoms' (groups B or E). This is the threshold that influences whether to escalate from monotherapy to dual bronchodilation or add ICS.
The minimum clinically important difference is 2 points. When monitoring treatment response, look for changes ≥2 — smaller changes may not represent meaningful clinical improvement.
CAT captures dimensions that mMRC misses: cough, phlegm, chest tightness, sleep, energy, and confidence leaving home. It gives a more complete picture of disease impact than breathlessness alone.
Administer CAT before the clinical consultation so results are available for discussion. Many practices use tablets or paper forms in the waiting room.
A rising CAT score over time, even within the same GOLD group, should prompt review of inhaler technique, adherence, smoking status, and comorbidities before escalating pharmacotherapy.

✓ when to use

✗ when not to use

clinical pearls

CAT ≥10 = GOLD 'more symptoms' (groups B or E). This is the threshold that influences whether to escalate from monotherapy to dual bronchodilation or add ICS.
The minimum clinically important difference is 2 points. When monitoring treatment response, look for changes ≥2 — smaller changes may not represent meaningful clinical improvement.
CAT captures dimensions that mMRC misses: cough, phlegm, chest tightness, sleep, energy, and confidence leaving home. It gives a more complete picture of disease impact than breathlessness alone.
Administer CAT before the clinical consultation so results are available for discussion. Many practices use tablets or paper forms in the waiting room.
A rising CAT score over time, even within the same GOLD group, should prompt review of inhaler technique, adherence, smoking status, and comorbidities before escalating pharmacotherapy.

COPD Assessment Test (CAT)

questionnaire

✓ when to use

✗ when not to use

clinical pearls

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