Table 1 Baseline characteristics of airway impairment assessed by IOS in patients with chronic obstruction pulmonary disease

Number, n (%)

309 (40.2)

459 (59.8)

540 (70.3)

228 (29.7)

288 (37.5)

480 (62.5)

362 (47.1)

406 (52.9)

300 (39.1)

468 (60.9)

251 (32.7)

517 (67.3)

Age

63.71 (7.26)

64.56 (7.33)

64.30 (7.07)

64.02 (7.85)

62.74 (7.15)

65.10 (7.26)*

63.03 (7.18)

65.28 (7.27)*

62.91 (7.18)

65.05 (7.27)*

62.17 (7.19)

65.21 (7.16)*

Male, n (%)

283 (91.6)

414 (90.2)

491 (90.9)

206 (90.4)

254 (88.2)

443 (92.3)

335 (92.5)

362 (89.2)

277 (92.3)

420 (89.7)

225 (89.6)

472 (91.3)

BMI

22.15 (2.93)

21.87 (3.38)

21.84 (3.12)

22.32 (3.39)

22.35 (3.09)

21.76 (3.26) ^†

22.13 (2.92)

21.86 (3.45)

22.10 (3.02)

21.91 (3.32)

22.44 (3.16)

21.76 (3.21) ^†

Smoking statue, n (%)

 Never

41 (13.3)

60 (13.1)

68 (12.6)

33 (14.5)

46 (16.0)

55 (11.5)

45 (12.4)

56 (13.8)

39 (13.0)

62 (13.2)

40 (15.9)

61 (11.8)

 Ever

72 (23.3)

154 (33.6) ^†

150 (27.8)

76 (33.3)

63 (21.9)

163 (34.0) ^†

86 (23.8)

140 (34.5) ^†

69 (23.0)

157 (33.5) ^†

57 (22.7)

169 (32.7) ^†

 Current

196 (63.4)

245 (53.4) ^†

322 (59.6)

119 (52.2)

179 (62.2)

262 (54.6) ^†

231 (63.8)

210 (51.7) ^†

192 (64.0)

249 (53.2) ^†

154 (61.4)

287 (55.5)

Pack-years

34.14 (29.26)

38.38 (33.18)

36.63 (30.92)

36.80 (33.59)

33.68 (30.03)

38.48 (32.58) ^†

34.87 (29.81)

38.28 (33.27)

34.35 (29.47)

38.17 (33.01)

32.95 (29.08)

38.49 (32.79) ^†

Family history of respiratory diseases, n (%)

54 (17.5)

92 (20.0)

99 (18.3)

47 (20.6)

54 (18.8)

92 (19.2)

67 (18.5)

79 (19.5)

54 (18.0)

92 (19.7)

42 (16.7)

104 (20.1)

Occupational exposures, n (%)

84 (27.2)

124 (27.0)

132 (24.4)

76 (33.3) ^†

77 (26.7)

131 (27.3)

112 (30.9)

96 (23.6) ^†

82 (27.3)

126 (26.9)

66 (26.3)

142 (27.5)

Biomass exposure, n (%)

110 (35.6)

178 (38.8)

204 (37.8)

84 (36.8)

102 (35.4)

186 (38.8)

132 (36.5)

156 (38.4)

107 (35.7)

181 (38.7)

87 (34.7)

201 (38.9)

History of CB, n (%)

18 (5.8)

41 (8.9)

42 (7.8)

17 (7.5)

19 (6.6)

40 (8.3)

25 (6.9)

34 (8.4)

19 (6.3)

40 (8.5)

12 (4.8)

47 (9.1) ^†

History of asthma, n (%)

2 (0.6)

20 (4.4) ^†

11 (2.0)

11 (4.8) ^†

2 (0.7)

20 (4.2) ^†

1 (0.3)

21 (5.2)*

1 (0.3)

21 (4.5) ^†

1 (0.4)

21 (4.1) ^†

Drug treatment, n (%)

126 (40.8)

249 (54.2)*

255 (47.2)

120 (52.6)

114 (39.6)

261 (54.4)*

151 (41.7)

224 (55.2)*

123 (41.0)

252 (53.8) ^†

98 (39.0)

277 (53.6)*

Clinical symptoms, (n%)

 Cough

109 (35.3)

218 (47.5) ^†

228 (42.2)

99 (43.4)

99 (34.4)

228 (47.5)*

133 (36.7)

194 (47.8) ^†

106 (35.3)

221 (47.2) ^†

82 (32.7)

245 (47.4)*

 Phlegm

127 (41.1)

268 (58.4)*

272 (50.4)

123 (53.9)

119 (41.3)

276 (57.5)*

157 (43.4)

238 (58.6)*

122 (40.7)

273 (58.3)*

97 (38.6)

298 (57.6)*

 Wheeze

32 (10.4)

111 (24.2)*

91 (16.9)

52 (22.8)

32 (11.1)

111 (23.1)*

40 (11.0)

103 (25.4)*

31 (10.3)

112 (23.9)*

26 (10.4)

117 (22.6)*

 Dyspnea

87 (28.2)

237 (51.7)*

218 (40.4)

106 (46.7)

77 (26.7)

247 (51.6)*

104 (28.7)

220 (54.3)*

84 (28.0)

240 (51.4)*

64 (25.5)

260 (50.4)*

GOLD stage, n (%)

 GOLD 1

195 (63.1)

82 (17.9)*

225 (41.7)

52 (22.8)*

185 (64.2)

92 (19.2)*

207 (57.2)

70 (17.2)*

193 (64.3)

84 (17.9)*

173 (68.9)

104 (20.1)*

 GOLD 2

107 (34.6)

274 (59.7)*

242 (44.8)

139 (61.0)*

100 (34.7)

281 (58.5)*

144 (39.8)

237 (58.4)*

102 (34.0)

279 (59.6)*

76 (30.3)

305 (59.0)*

 GOLD 3

7 (2.3)

86 (18.7)*

62 (11.5)

31 (13.6)*

3 (1.0)

90 (18.8)*

11 (3.0)

82 (20.2)*

5 (1.7)

88 (18.8)*

2 (0.8)

91 (17.6)*

 GOLD 4

0 (0)

17 (3.7)*

11 (2.0)

6 (2.6)*

0 (0)

17 (3.5)*

0 (0)

17 (4.2)*

0 (0)

17 (3.6)*

0 (0)

17 (3.3)*

Emphysema on CT, (%)

59 (19.1)

170 (37.0)*

163 (30.2)

66 (28.9)

44 (15.3)

185 (38.5)*

77 (21.3)

152 (37.4)*

53 (17.7)

176 (37.6)*

38 (15.1)

191 (36.9)*

Air trapping on CT, (%)

139 (45.0)

310 (67.5)*

305 (56.5)

144 (63.2)

118 (41.0)

331 (69.0)*

166 (45.9)

283 (69.7)*

129 (43.0)

320 (68.4)*

98 (39.0)

351 (67.9)*