Table 4– COPD assessment test (CAT) known groups validity^#

COPD GOLD grades	GOLD I	GOLD II	GOLD III	GOLD IV		p-value
Agusti [9]	12.4±NR	14.4±NR	20.9±NR	20.9±NR		0.01
Ghobadi [17]	14.6±NR	21.1±NR	25.1±NR	28.4±NR		0.001
Jones [20]	16.2±8.8	16.3±7.9	19.3±8.2	22.3±8.7		0.0001^¶
Jones [22]	15.9±8.6	16.5±8.0	19.2±8.1	22.4±9.0		0.0001^¶
Kwon [25]	16.5±NR	16.0±NR	19.0±NR	21.3±NR		0.001
Marchand [27]	14.3±NR	16.6±NR	19.1±NR	23.7±NR		0.0001^¶
Okutan [37]	9.2±6.2	18.2±8.1	20.9±8.2	22.5±0.79		0.001⁺
Tsiligianni [14]	10.1±NR	10.5±NR	13.0±NR	26.0±NR		0.0023^¶
*Healthy individuals versus* COPD**	No COPD	COPD				p-value
Gao [33]	4.0±2.1	10.0±5.3				0.001
Jones [21] Turkey	8.1 (7.6–8.6)^§	20.9 (19.6–22.2)^§				0.0001
Jones [21] Arabic countries	5.4 (5.2–5.6)^§	16.6 (15.5–16.8)^§				0.0001
Miyazaki [28]	9.4±6.6	12.4±8.3				0.01
Nishimura [36]	5.8±4.4	7.3±5.2				0.001
Raghavan [40]	6.9±6.2	9.2±6.6				0.01
COPD status state	Stable	Exacerbation				p-value
Agusti [9]	15.8±8.1	22.4±8.4				0.01
Jones [5]	16.0±NR	20.7±NR				0.0001
Jones [20]	17.2±8.3	21.3±8.4				0.0001
mMRC score	0	1	2	3	4	p-value
Agusti [9]	8.7±NR	14.8±NR	18.3±NR	24.9±NR	28.1±NR	0.01
Marchand [27]	NA	12.7±NR^ƒ	19.9±NR	25.5±NR	25.2±NR	0.0001
Okutan [37]	7.7±2.2	13.9±6.1	21.7±5.9	27.5±2.2	27.3±9.7	0.021^##

Data are presented as subcategory total CAT score mean±sd, when available from the study, unless otherwise stated. COPD: chronic obstructive pulmonary disease; GOLD: Global Initiative for Chronic Obstructive Lung Disease; mMRC: modified Medical Research Council dyspnoea scale; NR: not reported; NA: not applicable. ^#: ability of the CAT to differentiate scores between subcategories known to vary on health status; ^¶: GOLD I and GOLD II are not significant; ⁺: GOLD II, GOLD III and GOLD IV are not significant; ^§: data are presented as mean (95% CI); ^ƒ: total CAT score for 0–1 mMRC score subcategory; ^##: mMRC scores 2, 3 and 4 are not significant.