The role of CAT in evaluating the response to treatment of patients with AECOPD

Figures & data

Table 1 Clinical characteristics of the patients

Variables	Characteristics	N	Mean±SD (%)
Sex	Male	201	89.3%
	Female	24	10.7%
Age		225	67.08±10.03
Smoke	Ex-smokers	122	54.22%
	Current smokers	103	45.78%
	Smoking index	225	58.69±58.07
Lung function	FEV1%	55	42.13±16.14
	FEV1/FVC	55	44.87±11.07
Comorbidities	Cardiovascular disease	92	40.89%
	OSAHS	18	8.0%
	Diabetes	24	10.67%
	Hypertension	101	44.89%
Treatment	Antibiotics	190	84.44%
	ICS or bronchodilator	195	86.67%
	Intravenous prednisone	116	51.56%
	Theophylline	43	19.11%
CAT	0–10	12	8.08±1.78
	11–20	48	16.83±2.75
	21–30	108	25.60±2.62
	31–40	57	33.60±2.27
mMRC	0–1	17	0.88±0.33
	2–4	208	3.02±0.67
GOLD grades	Mild	5	2.22%
	Moderate	21	9.33%
	Severe	189	84.0%
	Very severe	10	4.45%

Abbreviations: CAT, COPD assessment test; GOLD, Global Initiative for Chronic Obstructive Lung Disease; ICS, inhaled corticosteroids; mMRC, modified Medical Research Council; OSAHS, obstructive sleep apnea–hypopnea syndrome.

Figure 1 The flowchart for screening patients.

Abbreviations: AECOPD, acute exacerbation of COPD; CAT, COPD assessment test.

Table 2 Changes in CAT scores between the two visits in different health statuses

Health status	Cases	CAT score at admission	CAT score at the second visit	Changes in CAT score	P-value
Total	225	24.82±7.41	17.41±7.35a	7.37±6.60	<0.001
Much better	112	27.13±6.18	15.06±5.29a	12.07±4.48	<0.001
Slightly better	71	23.87±7.61	18.63±7.63a	5.24±3.51	<0.001
No change	25	19.16±8.79	17.92±8.64a	1.24±1.53	<0.001
Slightly worse	13	22.30±6.56	25.53±7.23a	−3.23±2.31	<0.001
Much worse	4	20.50±1.29	32.00±4.08	−11.50±3.11	0.178

Note:

a Significant difference in CAT score between the two visits.

Abbreviation: CAT, COPD assessment test.

Figure 2 The comparison of the changes in CAT score in AECOPD patients with different health statuses.

Notes: *P<0.05 vs much better group; ^#P<0.05 vs slightly better group; ^▲P<0.05 vs no change group; ^▼P<0.05 vs slightly worse group; ^⋆P<0.05 vs much worse group.
Abbreviations: AECOPD, acute exacerbation of COPD; CAT, COPD assessment test.

Table 3 Changes in CAT scores between responders and nonresponders

Subjects	Cases	CAT score at admission	CAT score at the second visit	Changes in CAT score	P-value
Responders	183	25.87±6.94	16.45±6.52	9.37±5.24	<0.001
Nonresponders	42	20.26±7.75	21.62±9.18	−1.36±4.35

Abbreviation: CAT, COPD assessment test.

Table 4 The correlation between CAT score and health status, and improvement in FEV₁% and FEV₁

CAT score (N=225)	Health status (N=225)		ΔFEV1% (N=55)		ΔFEV1 (N=55)
	Rho	P-value	r	P-value	r	P-value
CAT at admission	−0.331	<0.001a	0.16	0.23	0.17	0.22
CAT at the second visit	0.333	<0.001a	−0.22	0.11	−0.19	0.16
Changes in CAT	−0.824	<0.001a	0.387	0.001a	0.363	0.007a

Notes: Δ means the changes of the parameters between the two visits.

a Statistic difference of the correlation between the two parameters.

Abbreviation: CAT, COPD assessment test.

Figure 3 Relationship between the CAT score at admission and length of hospital stay.

Abbreviation: CAT, COPD assessment test.

Figure 4 Relationship between the CAT score at the second visit and length of hospital stay.

Abbreviation: CAT, COPD assessment test.

Figure 5 Relationship between the changes in CAT score and length of hospital stay.

Abbreviation: CAT, COPD assessment test.

Figure 6 The ROC curve for the cutoff point of CAT score improvements to differentiate responders and nonresponders.

Notes: The AUC was 0.973; the sensitivity and specificity were 86.9% and 97.4%, respectively.

Abbreviations: AUC, area under the curve; CAT, COPD assessment test; ROC, receiver operating characteristic.

Figure 7 The ROC curve for the cutoff point of CAT score improvements to differentiate between patients in the slightly better group and no-change group.

Note: The AUC was 0.900; the sensitivity and specificity were 70% and 96%, respectively.
Abbreviations: AUC, area under the curve; CAT, COPD assessment test; ROC, receiver operating characteristic.

Figure S1 The number of the patients who received standard treatment.

Notes: This was a one-year follow-up study. In total, 189 patients were recruited into our study. All of them accepted three visits after being recruited (at 3 months, at 6 months, and at 12 months). If the patients reported they took their drugs everyday based on the prescription at every visit, they would be classified as those who received regular treatment. The rest were those who didn’t receive regular treatment. We found that only one-third of the patients received regular treatment.

Table S1 The detailed information of the comorbidities of patients who reported no change

Health status	CAT score at admission	CAT score at the second visit	Changes in CAT	Comorbidities
No change	25	25	0	N
No change	14	14	0	N
No change	28	30	−2	N
No change	12	9	3	Diabetes
No change	20	20	0	H
No change	6	6	0	N
No change	28	25	3	CHD
No change	10	10	0	N
No change	5	3	2	N
No change	16	15	1	N
No change	17	15	2	N
No change	5	5	0	N
No change	26	26	0	H
No change	17	14	3	CHD, H
No change	25	23	2	N
No change	18	18	0	N
No change	29	29	0	H
No change	9	9	0	N
No change	28	24	4	CHD, H
No change	24	21	3	CHD
No change	33	31	2	N
No change	22	20	2	N
No change	9	6	3	Diabetes
No change	34	31	3	OSAHS
No change	19	19	0	N

Abbreviations: CAT, COPD assessment test; CHD, coronary heart disease; H, hypertension; N, no comorbidity; OSAHS, obstructive sleep apnea–hypopnea syndrome.