Table 4 Clinical characteristics and prevalence of comorbidities in the three comorbidity clusters

Age, years (IQR)

68.0 (57.0–75.0), p = 0.22

69.0 (58.0–75.0), p = 0.99

71.0 (61.0–77.0), p = 0.23

Male, %

59.7, p = 0.91

63.5, p = 0.45

57.5, p = 0.51

Never smokers, %

36.4, p = 0.78

37.8, p = 0.53

31.4, p = 0.37

Current smokers, %

13.0, p = 0.53

12.2, p = 0.37

19.8, p = 0.13

Former smokers, %

50.6, p = 0.86

50.0, p = 0.96

48.8, p = 0.83

Missing, %

0.0

3.5

1.2

Pack years (IQR)

20.0 (15.0–30.0), p = 0.18

25.5 (13.0–40.0), p = 0.47

35.0 (10.0–43.0), p = 0.56

Body mass index (SD)

27.2 (5.3), p = 0.14

29.8 (4.9), p = 0.001^†

26.8 (4.8), p = 0.03*

FVC, % predicted (SD)

77.4 (21.3), p = 0.52

71.1 (26.4), p = 0.03*

79.3 (24.8), p = 0.11

DLCO, % predicted (SD)

53.8 (20.5), p = 0.06

44.5 (19.7), p = 0.006*

51.6 (19.8), p = 0.36

6MWD, m (SD)

377.7 (123.6), p = 0.19

304.2 (139.5), p < 0.0001*

394.6 (127.2), p = 0.005^†

Total number of comorbidities, n (SD)

0.9 (1.1), p < 0.0001*

3.4 (2.0), p < 0.0001^†

2.0 (1.1), p = 0.41

Emphysema, %

5.7, p < 0.0001*

25.7, p = 0.01*

70.3, p < 0.0001^†

Pulmonary hypertension, %

3.9, p = 0.11

14.1, p = 0.01^†

5.7, p = 0.33

Venous thromboembolism, %

3.9, p = 0.22

11.8, p = 0.03^†

4.6, p = 0.31

Sleep apnea, %

2.6, p = 0.28

8.2, p = 0.07

3.4, p = 0.46

Coronary artery disease, %

22.1, p = 0.14

28.2, p = 0.0005^†

1.1, p < 0.0001*

Dyslipidemia, %

6.5, p = 0.06

20.0, p = 0.009^†

10.3, p = 0.46

Arterial hypertension, %

0.0, p < 0.0001*

63.5, p < 0.0001^†

50.6, p = 0.008^†

Atrial fibrillation, %

10.4, p = 0.46

7.1, p = 0.58

8.0, p = 0.87

Chronic heart failure, %

7.8, p = 0.56

8.2, p = 0.40

3.4, p = 0.16

Heart valve disease, %

3.9, p = 0.65

8.2, p = 0.07

2.3, p = 0.17

Cerebrovascular disease, %

7.8, p = 0.69

3.5, p = 0.14

9.2, p = 0.28

Chronic renal failure, %

1.3, p = 0.19

8.2, p = 0.005^†

1.1, p = 0.13

Diabetes, %

0.0, p < 0.0001*

55.3, p < 0.0001^†

0.0, p < 0.0001*

Osteoporosis, %

5.2, p = 0.22

8.2, p = 0.94

11.5, p = 0.20

Gastro-esophageal reflux disease, %

0.0, p < 0.0001*

51.8, p < 0.0001^†

2.3, p < 0.0001*

Thyroid disease, %

7.8, p = 0.56

9.4, p = 0.17

2.3, p = 0.05

Liver failure, %

1.3, p = 0.56

0.0, p = 0.31

1.1, p = 0.66

Lung cancer, %

0.0, p = 0.34

2.4, p = 0.049^†

0.0, p = 0.30

Cancer, %

1.3, p = 0.03*

4.7, p = 0.43

12.6, p = 0.003†

Depression, %

1.3, p = 0.01*

7.1, p = 0.81

13.8, p = 0.007†