COPD Assessment Test (CAT)
Quantifies COPD symptom impact on health status and quality of life
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Why use it
Recommended by GOLD 2024 guidelines as the preferred symptom assessment tool for COPD classification. More comprehensive than mMRC (which captures dyspnea only). Sensitive to treatment response and exacerbations. Validated in >9,000 patients across 15 countries.
About
The COPD Assessment Test (CAT) is an 8-item patient-reported outcome measure that quantifies the impact of COPD on health status and quality of life. Scores range from 0 to 40. The CAT is a key component of the GOLD ABCD/ABE patient assessment system alongside spirometry and exacerbation history. It has better responsiveness to clinical change than FEV1 alone and correlates strongly with exercise capacity and 6-minute walk distance.
When to use
- COPD classification and GOLD ABCD/ABE grouping
- Monitoring response to bronchodilators, pulmonary rehabilitation, or oxygen therapy
- Baseline assessment before and after exacerbation
- Annual COPD follow-up visits
- Identifying patients with high symptom burden who may benefit from more intensive therapy
Formula
Pearls & pitfalls
- CAT ≥ 10 is the "more symptoms" threshold in GOLD 2024 ABE classification (replaces the ABCD system).
- Minimal Clinically Important Difference (MCID) is 2 points — changes ≥ 2 points are meaningful.
- CAT is not disease-specific — it may detect any chronic respiratory symptom burden.
- The CAT is freely available at www.catestonline.org in multiple languages.
- mMRC < 2 vs. ≥ 2 is an alternative to CAT < 10 vs. ≥ 10 for GOLD classification.
- CAT can be used at every office visit to track longitudinal changes — higher scores predict future exacerbations.
Next steps
CAT < 10: Low symptom impact (GOLD Group A or E depending on exacerbations). CAT ≥ 10: Higher symptom impact (GOLD Group B or E). If CAT ≥ 10 with ≥ 2 exacerbations or ≥ 1 hospitalization: Group E — consider triple inhaler therapy, roflumilast, or azithromycin.
Evidence
Jones PW et al. (Eur Respir J 2009) validated CAT in 1,817 COPD patients. CAT correlated with SGRQ (r = 0.80), 6MWD, exacerbation frequency, and FEV1. GOLD guidelines (since 2011) incorporate CAT as the recommended symptom assessment tool.