Role of the Emphysema Index Combined with the Chronic Obstructive Pulmonary Disease Assessment Test Score in the Evaluation of Chronic Obstructive Pulmonary Disease

Table 2

Basic information of patients in the four chronic obstructive pulmonary disease groups.

Variables	EI < 16%		EI ≥ 16%		value
	CAT < 10 (Group 1, n = 20)	CAT ≥ 10 (Group 2, n = 89)	CAT < 10 (Group 3, n = 32)	CAT ≥ 10 (Group 4, n = 136)
Sex, n (%)					<0.001^a
Male	14 (70.0)	68 (76.4)	31 (96.93)^#	129 (94.9)^#,
Female	6 (30.0)	21 (23.6)	1 (3.1)	7 (5.1)
Age (years)	63.4 ± 11.3	67.7 ± 11.0	67.8 ± 11.0	67.7 ± 9.6	0.350^b
COPD education					0.030^a
Yes, n (%)	13 (65.0)	27 (30.3)^#	14 (43.8)	56 (41.2)
No, n (%)	7 (35.0)	62 (69.7)	18 (56.2)	80 (58.8)
BMI (kg/m^2)	23.8 (21.6,27.3)	25.7 (22.5,27.7)	22.7 (19.5,25.5)	22.2 (19.6,25.1)	<0.001^c
Smoking (pack-years)	40.0 (32.5,62.5)	36.5 (20.0,50.0)	40.0 (20.0,60.0)	40.0 (25.0,50.0)	0.302^c
WBC (×10^9/L)	7.48 (5.20,9.19)	6.71 (5.51,8.24)	7.30 (5.38,10.34)	6.49 (5.24,8.44)	0.587^c
N (%)	71.56 ± 12.67	71.28 ± 10.44	71.76 ± 15.07	71.70 ± 11.15	0.994^b
E (%)	0.80 (0.40,3.48)	1.40 (0.35,3.05)	1.60 (0.48,2.90)	1.50 (0.50,3.08)	0.869^c
PaO2 (mmHg)	80.0 (64.5,90.8)	76.0 (66.0,88.0)	75.5 (66.0,82.8)	73.0 (62.5,84.8)	0.628^c
PaCO2 (mmHg)	42.0 (37.0,45.8)	39.0 (35.0,44.0)	42.0 (37.0,46.5)	43.5 (39.0,49.0)	<0.001^c

COPD = chronic obstructive pulmonary disease, CAT = COPD Assessment Test, EI = emphysema index, BMI = body mass index, WBC = white blood cell count, N = neutrophil count, E = eosinophil count, and Pa = partial pressure. ^aChi-squared analysis (Bonferroni method for difference between groups), ^banalysis of variance (Tukey’s method for difference between groups), and ^cKruskal–Wallis test (Bonferroni method for difference between groups). , versus Group 1; , versus Group 2.