Clinical phenotypes of COPD and health-related quality of life: a cross-sectional study

Figures & data

Table 1 Demographic and clinical characteristics of COPD patients according to their clinical phenotypes

Characteristics	COPD phenotype (n, %)
	NON-AE 54 (28.6)	AE NON-CB 35 (18.5)	AE CB 75 (39.7)	ACOS 25 (13.2)	P-value
Age (years, mean ± SD)	74.1±8.1	72.7±8.7	70.7±9.2	70.0±13.1	0.151
Gender (n, %)
Male	50 (92.6)	32 (91.4)	70 (93.3)	23 (92.0)	0.986
Female	4 (7.4)	3 (8.6)	5 (6.7)	2 (8.0)
Ethnicity (n, %)
Malay	19 (35.2)	12 (34.3)	32 (42.7)	10 (40.0)	0.734
Chinese	27 (50.0)	18 (51.4)	30 (40.0)	9 (36.0)
Indian	8 (14.8)	5 (14.3)	13 (17.3)	6 (24.0)
Smoking status (n, %)
Never smoker	2 (3.7)	3 (8.6)	4 (5.3)	3 (12.0)	0.348
Previous	40 (74.1)	19 (54.3)	55 (73.3)	15 (60.0)	0.601
Current	12 (22.2)	13 (37.1)	16 (21.3)	7 (28.0)
Quantity of cigarettes smoked (pack-years, mean)	42.3±30.4	44.6±30.1	43.9±27.9	39.0±35.4
Dyspnea (mean ± SD; 95% CI)	1.8±1.3; 1.5–2.2	2.0±1.2; 1.6–2.4	2.7±1.1; 2.4–2.9	2.2±1.4; 1.6–2.8	0.002
PB-FEV1 (%, mean ± SD; 95% CI)	57.8±20.2; 52.3–63.4	51.1±23.1; 43.2–59.0	48.2±23.6; 42.8–53.7	52.8±16.2; 46.1–59.5	0.025
Exacerbations (mean ± SD; 95% CI)
Total	0.5±1.8; 0.1–1.0	1.9±1.9; 1.3–2.6	4.8±6.8; 3.2–6.4	3.4±5.2; 1.3–5.6	<0.001
Moderate	0.4±1.3; 0.1–0.8	0.7±1.0; 0.4–1.1	2.9±5.4; 1.7–4.2	1.9±3.2; 0.6–3.3	<0.001
Severe	0	1.3±1.2; 0.9–1.7	1.9±2.1; 1.4–2.4	1.5±2.5; 0.5–2.6	<0.001

Abbreviations: ACOS, asthma-COPD overlap syndrome phenotype; AE CB, exacerbator with chronic bronchitis phenotype; AE NON-CB, exacerbator with emphysema phenotype; NON-AE, non-exacerbator phenotype; PB-FEV₁, post-bronchodilator forced expiratory volume in 1 second.

Figure 1 Algorithm of patients’ recruitment into the study.

Abbreviation: PB-FEV₁/FVC, ratio of post-bronchodilator force expiratory volume in 1 second/forced vital capacity.

Table 2 CAT and SGRQ-c scores of COPD patients according to their clinical phenotypes

Parameters	COPD phenotype				P-value
	NON-AE	AE NON-CB	AE CB	ACOS
CAT score (mean ± SD; 95% CI)
Total	18.0 ± 8.0; 15.8-20.2	15.8 ± 8.0; 13.1-18.6	23.6 ± 8.0; 21.8-25.4	18.3 ± 10.1; 14.0-22.7	<0.001
Cough (CAT 1)	2.5 ± 1.2; 2.1-2.8	2.1 ± 1.3; 1.6-2.5	3.2 ± 1.2; 2.9-3.5	2.6 ± 1.6; 2.0-3.3	<0.001
Phlegm (cat 2)	2.6 ± 1.8; 2.1-3.0	1.6 ± 1.6; 1.0-2.1	3.3 ± 1.7; 2.9-3.7	2.4 ± 1.9; 1.6-3.2	<0.001
Chest tightness (CAT 3)	1.4 ± 1.7; 0.9-1.8	1.7 ± 1.5; 1.2-2.2	2.6 ± 1.6; 2.2-2.9	2.2 ± 1.7; 1.5-2.9	<0.001
Breathlessness (CAT 4)	3.4 ± 1.7; 3.0-3.9	3.2 ± 1.5; 2.7-3.7	4.0 ± 1.3; 3.7-4.2	3.0 ± 1.7; 2.3-3.7	0.020
Activity limitation (CAT 5)	2.5 ± 1.8; 2.0-3.0	2.0 ± 1.7; 1.4-2.6	3.0 ± 1.6; 2.6-3.4	2.3 ± 1.9; 1.5-3.1	0.038
Confidence in leaving home (CAT 6)	1.7 ± 1.9; 1.2-2.2	1.6 ± 1.8; 1.0-2.2	2.4 ± 1.6; 2.1-2.8	1.9 ± 1.9; 1.1-2.7	0.022
Sleep (CAT 7)	1.6 ± 1.6; 1.2-2.1	1.6 ± 1.6; 1.0-2.1	2.2 ± 1.6; 1.8-2.5	1.8 ± 1.8; 1.1-2.5	0.127
Energy (CAT 8)	2.4 ± 1.1; 2.1-2.7	2.2 ± 1.5; 1.7-2.7	3.0 ± 1.4; 2.7-3.4	2.2 ± 1.6; 1.5-2.8	0.004
SGRQ-c score, % (mean ± SD; 95% CI)
Total	42.6 ± 20.1; 37.1-48.1	44.0 ± 21.4; 36.6-51.4	61.5 ± 20.9; 56.7-66.3	51.5 ± 25.9; 40.8-62.2	<0.001
Symptoms	36.8 ± 19.9; 31.4-42.3	43.3 ± 23.6; 35.3-51.5	61.7 ± 20.4; 57.0-66.4	59.2 ± 25.1; 48.9-69.6	<0.001
Activities	48.9 ± 32.5; 40.1-57.8	56.8 ± 27.8; 47.3-66.4	70.5 ± 25.1; 64.7-76.2	58.0 ± 34.6; 43.8-72.3	0.001
Impact	40.9 ± 20.1; 35.4-46.3	36.9 ± 24.8; 28.4-45.5	56.0 ± 27.2; 49.8-62.3	44.8 ± 32.1; 31.2-58.1	0.001

Abbreviations: ACOS, asthma-COPD overlap syndrome phenotype; AE CB, exacerbator with chronic bronchitis phenotype; AE NON-CB, exacerbator with emphysema phenotype; CAT, COPD Assessment Test; NON-AE, non-exacerbator phenotype; SGRQ-c, St Georges Respiratory Questionnaire for COPD.

Figure 2 Score of CAT items according to COPD clinical phenotypes.

Abbreviations: ACOS, asthma-COPD overlap syndrome phenotype; AE CB, exacerbator with chronic bronchitis phenotype; AE NON-CB, exacerbator with emphysema phenotype; CAT, COPD Assessment Test; NON-AE, non-exacerbator phenotype.

Figure 3 Total and component scores of SGRQ-c according to COPD clinical phenotypes.

Abbreviations: ACOS, asthma-COPD overlap syndrome phenotype; AE CB, exacerbator with chronic bronchitis phenotype; AE NON-CB, exacerbator with emphysema phenotype; NON-AE, non-exacerbator phenotype; SGRQ-c, St Georges Respiratory Questionnaire for COPD.

Data availability

The study data will be shared on request due to patients’ confidentiality and can be obtained from the corresponding author.