Table 2 Baseline characteristics of patients categorised as GOLD A and B

 Gender (% Male)

58.8

67.3

0.41

 Pack years

44.5 [10.0–135.0]

45 [10.0–220.0]

0.53

 Smoking status (% Current)

15.2

36.5

0.031

 BMI (Kg/m²)

26.1 [20.6–47.0]

27.2 [16.5–49.2]

0.73

 FFMI (Kg/m²)

17.3 [12.9–28.7]

17.6 [10.0–27.0]

0.92

 Chronic bronchitis (%)

21.2

57.4

0.0003

 Exacerbations (1 year prior)

0.0 [0.0–1.0]

0.0 [0.0–1.0]

0.11

 Cardiovascular comorbidity any (%)

61.8

82.2

0.019

 Comorbidities any (%)

35.3

16.8

0.03

 SGRQ total

19.3 [1.0–40.0]

40.9 [5.7–82.4]

<0.0001

 SGRQ symptoms

29.5 (16.5)

55.3 (17.8)

<0.0001

 SGRQ impact

12.0 [3.0–24.0]

25.0 [0.0–75.5]

<0.0001

 SGRQ activity

34.8 (18.5)

58.9 (22.6)

<0.0001

 CAT

6.0 [2.0–9.0]

16.0 [4.0–39.0]

<0.0001

 CES-D

5.0 [1.0–6.0]

11.5 [1.0–4.0]

<0.0001

 6MWD (metres)

457.0 [169.0–636.0]

405.7 [119.0–702.0]

0.07

 Vital capacity %

102.3 (22.5)

100.7 (17.9)

0.73

 Total lung capacity %

108.9 (16.1)

109.2 (20.1)

0.96

 Residual volume %

130.6 [89.1–179.9]

132.0 [63.0–286.0]

0.90

 Inspiratory capacity %

87.1 (23.0)

89.5 (21.3)

0.65

 FRC %

125.8 (24.0)

128.7 (33.2)

0.71

 DLCO %

70.8 [56.0–116.5]

63.0 [28.0–106.0]

0.05

 KCO %

86.8 [64.0–126.5]

76.4 [35.0–137.0]

0.13

 VA %

84.2 (13.3)

80.8 (10.7)

0.25

 Post FEV₁ %

71.0 (15.2)

68.3 (11.4)

0.27

 Reversibility %

9.8 [4.0–16.0]

6.7 [−3.0–+38.0]

0.13

 Reversibility mls

150.0 [−40.0–+290.0]

100.0 [−80.0–+670.0]

0.21

 Bacterial load (genome copies/ml)

7.11 × 10⁶ [0–1.81 × 10¹⁰]

7.74 × 10⁴ [0–4.91 × 10⁸]

0.29

 Colonised (% >1 × 10⁴ total PPM)

63.7

55.6

0.75

 CRP (mg/L)

3.0 [1.0–22.0]

3.0 [1.0–157.0]

0.35

 WBC (10⁹/L)

6.8 [3.6–12.0]

7.3 [5.0–12.6]

0.11

 Eosinophils (10⁹/L)

0.2 [0.0–0.8]

0.2 [0.0–0.9]

0.83