Skip to main content

Table 1 Clinical characteristics of participants by spirometric lung function class

From: Preserved ratio impaired spirometry is associated with small airway dysfunction and reduced total lung capacity

Characteristic

Healthy control

(n = 628)

PRISm

(n = 126)

Spirometry-defined COPD (n = 685)

Age, years

57.8 ± 7.7

60.9 ± 8.3*†

64.9 ± 7.1

Male sex, n (%)

389 (61.9)

75 (59.5)†

631 (92.1)

Body mass index, kg/m2

23.6 ± 3.1

23.3 ± 3.5†

22.3 ± 3.3

Smoking status, n (%)

   

Never smoked

318 (50.6)

68 (54.0)†

89 (13.0)

Former smoking

86 (13.7)

20 (15.9)†

218 (31.8)

Current smoking

224 (35.7)

38 (30.2)†

378 (55.2)

Smoking index, pack-years

19.7 ± 28.6

20.1 ± 28.3†

35.0 ± 30.4

Biomass exposure, n (%)

250 (39.8)

46 (36.5)

287 (41.9)

Occupational history to dusts/gases/fumes, n (%)

110 (17.5)

30 (23.8)

216 (31.5)

Family history of respiratory diseases, n (%)

63 (10.1)

16 (12.7)†

145 (21.3)

History of pulmonary tuberculosis, n (%)

11 (5.5)

2 (8.0)†

25 (28.1)

Chronic cough during childhood, n (%)

6 (18.3)

4 (3.2)

32 (4.7)

Previous medication for respiratory disease, n (%)

66(10.5)

18 (14.3)†

351 (51.2)

mMRC dyspnea scale score

0.2 ± 0.5

0.3 ± 0.5†

0.5 ± 0.7

CAT score

3.8 ± 4.2

4.5 ± 5.7†

5.7 ± 5.6

Acute respiratory events / exacerbations during preceding year, n (%)

21 (3.4)

9 (7.3)†

96 (14.0)

Self-reported diagnosed COPD, n (%)

12 (1.9)

5 (4.0)†

252 (36.8)

Self-reported diagnosed asthma, n (%)

3 (0.5)

1 (0.8)

21 (3.1)

Comorbidities, n (%)

   

Hypertension

100 (15.9)

24 (19.0)

112 (16.4)

Diabetes

26 (4.1)

12 (9.5)*†

25 (3.6)

Coronary heart disease

24 (3.8)

4 (3.2)

24 (3.5)

Cerebral infarction

13 (2.1)

4 (3.2)

22 (3.2)

Chronic cough, n (%)

109 (17.4)

27 (21.4)†

296 (43.2)

Chronic phlegm, n (%)

142 (22.6)

36 (28.6)†

332 (48.5)

Dyspnea, n (%)

119 (19.0)

30 (23.8)†

280 (40.9)

Wheeze, n (%)

36 (5.7)

16 (12.7)*

130 (19.0)

  1. Data are mean ± standard deviation or n (%)
  2. Abbreviations: PRISm, preserved ratio impaired spirometry; COPD, chronic obstructive pulmonary disease; mMRC, modified British medical research council score; CAT, COPD assessment test
  3. * P < 0.05 compared with healthy control after adjusting for multiple comparisons using Bonferroni correction method
  4. † P < 0.05 compared with COPD after adjusting for multiple comparisons using Bonferroni correction method