A comparison of the assessment of health status between CCQ and CAT in a Chinese COPD clinical population: a cross-sectional analysis

Figures & data

Table 1 Demographic and clinical characteristics of participants with COPD

Characteristics	All patients (n=372)
Age (years)	62.2±8.3
Gender
Male	319 (85.8%)
Female	53 (14.2%)
BMI (kg/m^2)	22.3±3.5
Smoking pack years	40.0±32.2
Exacerbations in the last 12 months
0	175 (47.0%)
1	104 (28.0%)
≥2	93 (25.0%)
FEV1/FVC	0.44±0.13
FEV1% predicted	48.6±18.9
mMRC	1.9±0.9
CAT	15.4±6.0
Mild (0–10)	85 (22.8%)
Medium (11–20)	211 (56.7%)
High (21–30)	72 (19.4%)
Very high (31–40)	4 (1.1%)
CCQ	2.0±0.7
Acceptable (CCQ<1)	10 (2.7%)
Acceptable for moderate disease (1≤CCQ<2)	172 (46.2%)
Instable-severe limited (2≤CCQ<3)	156 (41.9%)
Very instable-very severe limited (CCQ≥3)	34 (9.2%)
GOLD grades
1: Mild	30 (8.1%)
2: Moderate	122 (32.8%)
3: Severe	172 (46.2%)
4: Very severe	48 (12.9%)

Note: Data presented as mean ± SD or n (%).

Abbreviations: BMI, body mass index; CAT, COPD Assessment Test; CCQ, Clinical COPD Questionnaire; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; GOLD, global initiative for chronic obstructive lung disease; mMRC, modified Medical Research Council dyspnea score.

Table 2 Kappa of agreement for the symptom groups by CAT and CCQ (cutpoint =1.5)

CCQ cutpoint =1.5	CAT
	Groups A and C	Groups B and D	Total
Groups A and C	44	38	82
Groups B and D	22	268	290
Total	66	306	372

Note: Kappa=0.495, moderate agreement.

Abbreviations: CAT, COPD Assessment Test; CCQ, Clinical COPD Questionnaire.

Table 3 Kappa of agreement for the symptom groups by CAT and CCQ (cutpoint =1.0)

CCQ cutpoint =1.0	CAT
	Groups A and C	Groups B and D	Total
Groups A and C	7	3	10
Groups B and D	59	303	362
Total	66	306	372

Note: Kappa=0.144, slight agreement.

Abbreviations: CAT, COPD Assessment Test; CCQ, Clinical COPD Questionnaire.

Figure 1 Differences in classification of symptom group using CAT and CCQ.

Abbreviations: CAT, COPD Assessment Test; CCQ, Clinical COPD Questionnaire.

Table 4 FEV₁/FVC, FEV₁% predicted, exacerbation frequency and mMRC in different CAT categories

Variables	Mild 0≤CAT≤10	Medium 11≤CAT≤20	High 21≤CAT≤30	P-value
FEV1/FVC	0.47±0.13#,▲	0.44±0.12*,▲	0.39±0.14*,#	<0.001
FEV1 % predicted	54.73±20.91#,▲	48.28±17.48*,▲	42.72±18.79*,#	<0.001
Exacerbation frequency in the last year	0.28±0.59#,▲	0.92±1.22*,▲	1.86±1.37*,#	<0.001
mMRC	1.18±0.69#,▲	1.79±0.83*,▲	2.50±0.71*,#	<0.001

Notes:

* P<0.05 vs 0≤CAT≤10;

# P<0.05 vs 11≤CAT≤20;

▲ P<0.05 vs 21≤CAT≤30.

Abbreviations: CAT, COPD Assessment Test; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; mMRC, modified Medical Research Council.

Table 5 FEV₁/FVC, FEV₁% predicted, exacerbation frequency, and mMRC in different CCQ categories

Variables	Acceptable CCQ<1	Acceptable for moderate disease 1≤CCQ<2	Instable-severe limited 2≤CCQ<3	Very instable-very severe limited CCQ≥3	P-value
FEV1/FVC	59.90±15.82▲,¶	46.19±12.11▲,¶	42.05±12.33*,#	37.51±11.52*,#	<0.001
FEV1 % predicted	62.53±21.06▲,¶	51.53±18.10▲,¶	46.65±18.94*,#,¶	38.34±17.39*,#,▲	<0.001
Exacerbation frequency in the last year	0.10±0.32#,▲,¶	0.49±0.98*,▲,¶	1.26±1.22*,#	2.44±1.48*,#,▲	<0.001
mMRC	0.70±0.48#,▲,¶	1.54±0.79*,▲,¶	2.19±0.73*,#,¶	2.68±0.77*,#,▲	<0.001

Notes:

* P<0.05 vs CCQ<1;

# P<0.05 vs 1≤CCQ<2;

▲ P<0.05 vs 2≤CCQ<3;

¶ P<0.05 vs CCQ≥3.

Abbreviations: CCQ, clinical COPD questionnaire; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; mMRC, modified Medical Research Council dyspnea score.

Table 6 Score of CAT and CCQ by GOLD grades

Variables	Grade 1, n=30	Grade 2, n=122	Grade 3, n=172	Grade 4, n=48	P-value
CAT	13.80±6.27¶	13.89±5.28▲,¶	15.56±5.61#,¶	19.77±6.70*,#,▲	<0.001
CCQ total	1.76±0.70▲,¶	1.85±0.61▲,¶	2.06±0.69*,#,¶	2.51±0.93*,#,▲	<0.001
CCQ symptom	2.02±0.84¶	2.06±0.76¶	2.16±0.80¶	2.50±1.03*,#,▲	=0.013
CCQ function	1.53±0.81▲,¶	1.70±0.68▲,¶	1.97±0.76*,#	2.53±1.02*,#▲	<0.001
CCQ mental	1.68±1.05	1.62±1.09¶	1.86±1.14	2.18±1.42#	=0.033
Exacerbation frequency	0.37±0.67▲,¶	0.79±1.20¶	1.06±1.31*	1.65±1.41*,#	<0.001

Notes:

* P<0.05 vs Grade 1;

# P<0.05 vs Grade 2;

▲ P<0.05 vs Grade 3;

¶ P<0.05 vs Grade 4.

Abbreviations: CAT, COPD Assessment Test; CCQ, clinical COPD questionnaire; GOLD, Global Initiative for Chronic Obstructive Lung Disease.

Table 7 Score of CAT and CCQ by exacerbation frequencies

Variables	Exacerbation frequency in the last 12 months			P-value
	AE=0, n=175	AE=1, n=104	AE≥2, n=93
CAT	12.69±5.11#,▲	15.61±4.76*,▲	20.33±5.57*,#	<0.001
CCQ total	1.70±0.60#,▲	2.02±0.47*,▲	2.64±0.81*,#	<0.001
CCQ symptom	1.84±0.68#,▲	2.13±0.64*,▲	2.78±0.92*,#	<0.001
CCQ function	1.60±0.69#,▲	1.91±0.60*,▲	2.52±0.94*,#	<0.001
CCQ mental	1.41±1.09#,▲	1.96±0.90*,▲	2.38±1.31*,#	<0.001
FEV1% predicted	53.84±19.32#,▲	45.37±18.22*	42.25±16.30*	<0.001

Notes:

* P<0.05 vs AE=0;

# P<0.05 vs AE=1;

▲ P<0.05 vs AE≥2.

Abbreviations: CAT, COPD Assessment Test; CCQ, clinical COPD questionnaire; FEV₁, forced expiratory volume in 1 second.

Figure 2 Distribution of CAT impact levels into different exacerbation frequencies.

Abbreviation: CAT, COPD Assessment Test.

Figure 3 Distribution of CCQ categories into different exacerbation frequencies.

Abbreviation: CCQ, clinical COPD questionnaire.

Table 8 Spearman rank correlations between health status questionnaires (CAT and CCQ), lung function, exacerbation frequency in the previous year, and mMRC dyspnea scale at baseline (n=372)

Variables	CAT	CCQ total	CCQ symptom	CCQ function	CCQ mental	mMRC	FEV1% predicted	Exacerbation frequency
CAT	–	0.776**	0.590**	0.688**	0.409**	0.614**	−0.270**	0.516**
CCQ total	–	–	0.734**	0.829**	0.628**	0.540**	−0.271**	0.542**
CCQ symptom	–	–	–	0.497**	0.273**	0.346**	−0.271**	0.439**
CCQ function	–	–	–	–	0.334**	0.578**	−0.321**	0.468**
CCQ mental	–	–	–	–	–	0.284**	−0.132*	0.339**
mMRC	–	–	–	–	–	–	−0.315**	0.342**
FEV1% predicted	–	–	–	–	–	–	–	−0.280**
Exacerbation frequency	–	–	–	–	–	–	–	–

Notes:

** P<0.01,

* P<0.05.

Abbreviations: CAT, COPD Assessment Test; CCQ, Clinical COPD Questionnaire; FEV₁, forced expiratory volume in 1 second; mMRC, modified Medical Research Council dyspnea score.

Figure 4 Spearman rank correlations between the CAT and the total CCQ score.

Abbreviations: CAT, COPD Assessment Test; CCQ, Clinical COPD Questionnaire.