Comparison of COPD Assessment Test and Clinical COPD Questionnaire to predict the risk of exacerbation

Figures & data

Table 1 Baseline characteristics of patients with and without exacerbation

Characteristics	Patients with an exacerbation (n=45)	Patients without an exacerbation (n=76)	P-value
Age, years	70.5±7.1	71.9±7.9	0.33
Male	44 (97.8)	74 (97.4)	0.89
BMI, kg/m^2	23.6±3.5	22.6±3.0	0.13
Smoking status
Former smoker	31 (72.1)	55 (73.3)	0.88
Current smoker	12 (27.9)	20 (26.7)
Pack-years	51.4±30.3	45.9±22.2	0.25
History of exacerbation in the past year
Exacerbations (yes, %)	26 (57.8)	22 (28.9)	<0.01
Frequency of exacerbation (no/year)	1.9±3.2	0.5±1.3	<0.01
Lung function
FEV1, L	1.5±0.5	1.7±0.5	0.06
FEV1, %	60.6±18.1	68.3±19.3	0.03
FVC, L	3.5±0.8	3.5±0.8	0.64
FVC, %	94.8±20.8	95.2±18.2	0.90
FEV1/FVC	43.0±11.2	48.7±10.3	<0.01
GOLD grade
1 (FEV1>80% predicted)	4 (8.9)	19 (25.0)	0.03
2 (FEV1 50%–79% predicted)	28 (62.2)	43 (56.6)
3 (FEV1 30%–49% predicted)	10 (22.2)	14 (18.4)
4 (FEV1 <30% predicted)	3 (6.7)	0 (0)
SGRQ score	40.3±19.5	34.7±17.7	0.11
mMRC grade	1.4±0.8	1.4±0.9	0.81
6MWD, m	443.0±109.7	424.5±124.3	0.43
CAT score	19.5±8.4	16.2±7.3	0.02
CCQ score	2.1±1.0	1.9±0.9	0.28

Note: Data are presented as number (%) or mean ± standard deviation.

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; 6MWD, 6-minute walk distance; SGRQ, St George’s Respiratory Questionnaire.

Figure 1 Flow diagram of the included study participants.

Abbreviations: CAT, COPD Assessment Test; CCQ, Clinical COPD Questionnaire; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity.

Figure 2 Correlation of CAT and CCQ scores with SGRQ (A and D), FEV₁% predicted (B and E), and 6MWD (C and F).

Abbreviations: CAT, COPD Assessment Test; CCQ, Clinical COPD Questionnaire; FEV₁, forced expiratory volume in 1 second; 6MWD, 6-minute walk distance; SGRQ, St George’s Respiratory Questionnaire.

Table 2 Predictors of exacerbation during 1-year follow-up period

Variables	Univariate analysis			Multivariate model 1a			Multivariate model 2b
	OR	95% CI	P-value	aOR	95% CI	P-value	aOR	95% CI	P-value
Age	0.98	0.93–1.02	0.33	0.98	0.92–1.03	0.39	1.00	0.95–1.07	0.85
Sex (male)	1.19	0.10–13.50	0.89	0.41	0.02–8.77	0.57	1.05	0.05–23.83	0.97
History of exacerbation in the past year	3.36	1.55–7.27	<0.01				3.36	1.38–8.19	0.01
Smoking packs/year	1.01	0.99–1.02	0.25	1.01	0.99–1.02	0.45	1.00	0.99–1.02	0.70
FEV1 (%)	0.98	0.96–1.00	0.03	0.98	0.96–1.00	0.14	0.98	0.96–1.01	0.18
FVC (%)	1.00	0.98–1.02	0.90
FEV1/FVC	0.95	0.92–0.99	0.01
mMRC ≥2	0.92	0.42–1.99	0.83
SGRQ ≥25	1.48	0.66–3.29	0.34
CAT ≥10	1.60	0.57–4.47	0.37
CAT ≥15	2.61	1.17–5.80	0.02	2.58	1.03–6.50	0.04	2.40	0.92–6.25	0.07
CCQ ≥1	1.07	0.34–3.43	0.90
CCQ ≥1.4	0.84	0.38–1.82	0.65
Use of LAMA	1.33	0.62–2.82	0.46
Use of ICS/LABA	1.25	0.59–2.61	0.56	0.98	0.42–2.26	0.96	1.03	0.43–2.45	0.95

Notes:

a Multivariate analysis was performed by adjusting for age, sex, baseline FEV₁%, CAT ≥15, smoking packs/year, and use of ICS/LABA.

b Multivariate analysis was performed by adjusting for age, sex, history of exacerbation in the past year, baseline FEV₁%, CAT ≥15, smoking packs/year, and use of ICS/LABA.

Abbreviations: aOR, adjusted OR; CAT, COPD Assessment Test; CCQ, Clinical COPD Questionnaire; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; ICS, inhaled corticosteroid; LABA, long-acting β₂ receptor agonist; LAMA, long-acting muscarinic receptor agonist; mMRC, modified Medical Research Council; OR, odds ratio; SGRQ, St George’s Respiratory Questionnaire.

Figure 3 The receiver operating characteristic curve to compare the prediction of exacerbation according to the different cutoff levels of symptom assessment tools.

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