Table 1 Baseline characteristics of the 20 participants of the cortisol sub-study (clinician assessment measures), separated by study arm according to their allocation at baseline

Age (years)

71.8 ± 2.9

72.0 (70.0–74.3)

68.3 ± 8.3

69.0 (62.0–71.0)

72.0 ± 12.4

74.0 (65.5–80.5)

H(2) = 1.69, p = 0.26

Sex (male)

5 (83.3%)

3 (37.5%)

1 (16.7%)

χ² = 5.69, p = 0.06

BMI (kg/m²)

30.0 ± 5.3

30.9 (25.2–34.5)

31.9 ± 7.5

33.0 (29.0–35.4)

24.8 ± 8.2

22.7 (17.4–33.1)

F = 1.66, p = 0.22

Charlson Comorbidity Index - age adjusted

5.2 ± 1.2

4.8 (4.0–6.3)

4.8 ± 1.5

5.0 (4.0–6.0)

5.3 ± 1.0

6.0 (4.0–6.0)

H(2) = 0.64, p = 0.73

AKPS

80

-

2 (25.0%)

2 (33.3%)

H(2) = 1.40, p = 0.50

70

4 (66.7%)

3 (37.5%)

3 (50.0%)

60

2 (33.3%)

3 (37.5%)

1 (16.7%)

Smoking status

Current smoker

-

2 (25.0%)

1 (16.7%)

χ² = 3.56, p = 0.47

Former smoker

6 (100%)

5 (62.5%)

5 (83.3%)

Never smoked

-

1 (12.5%)

-

End tidal CO₂(mmHg)^a

30.0 ± 7.3

32.0 (21.8–35.3)

29.4 ± 4.6

28.5 (26.1–34.0)

24.8 ± 4.8

26.3 (21.3–28.3)

F = 1.63, p = 0.23

Supplemental oxygen

1 (16.7%)

1 (12.5%)

1 (16.7%)

χ² = 2.84, p = 0.58

Relevant health conditions

Diabetes mellitus

(type I or II)

0 (0.0%)

1 (12.5%)

1 (16.7%)

χ² = 1.02, p = 0.60

Current history of psychiatric illness

3 (50%)

4 (50%)

2 (33.3%)

χ² = 0.47, p = 0.79

Previous history of psychiatric illness

0 (0%)

1 (12.5%)

0 (0%)

χ² = 1.93, p = 0.38

Relevant Medication

Steroid inhaler

4 (66.7%)

7 (87.5%)

7 (100%)

χ² = 2.68, p = 0.26

Anti-depressant

3 (50.0%)

2 (25.0%)

1 (16.7%)

χ² = 1.75, p = 0.42

Hormone therapy

0 (0%)

1 (12.5%)

0 (0%)

χ² = 1.58, p = 0.45

Immunosuppressant

0 (0%)

2 (25%)

1 (16.7%)

χ² = 1.70, p = 0.43

Chemo- or radiotherapy

0 (0%)

0 (0%)

0 (0%)

-

Availability of a carer

4 (66.7%)

6 (75.0%)

5 (83.3%)

χ² = 0.07, p = 0.97

mMRC

Grade 3

5 (83.3%)

8 (100%)

6 (100%)

χ² = 2.46, p = 0.29

Grade 4

1 (16.7%)

-

-

Breathlessness

Worst

6.3 ± 2.2

6.0 (4.6–8.6)

4.5 ± 1.5

4.8 (3.0–5.9)

5.9 ± 1.5

6.3 (4.6–6.9)

F = 2.18, p = 0.14

Average

5.1 ± 2.3

4.0 (3.4–7.8)

3.7 ± 1.1

3.8 (2.6–4.9)

4.7 ± 1.4

4.8 (3.4–5.5)

H(2) = 1.67, p = 0.43

Distress caused by breathlessness

3.8 ± 3.4

2.3 (1.3–7.5)

2.8 ± 2.4

2.3 (0.5–4.8)

4.3 ± 2.9

4.8 (1.3–6.3)

F = 0.45, p = 0.64

Quality of life (EQ-5D-5 L, VAS)

65.7 ± 23.9

60.0 (52.5–88.5)

51.3 ± 18.9

52.5 (32.5–71.3)

62.5 ± 24.8

62.5 (37.5–90.0)

F = 0.83; p = 0.45

Hospital Anxiety and Depression Scale (HADS)

HADS (Anxiety, 0–21)

7.0 ± 4.9

6.0 (3.8–12.3)

7.3 ± 4.2

8.0 (4.0–11.0)

4.8 ± 3.8

5.0 (1.5–7.8)

F = 0.61; p = 0.56

HADS (Depression, 0–21)

6.2 ± 4.1

5.5 (3.3–9.3)

6.3 ± 3.9

5.0 (3.0–9.0)

4.5 ± 3.8

3.0 (1.8–8.0)

F = 0.41; p = 0.67

Quality of sleep

Very good

1 (16.7%)

1 (12.5%)

1 (16.7%)

χ² = 7.95, p = 0.24

Good

4 (66.7%)

3 (37.5%)

1 (16.7%)

Poor

-

4 (50%)

4 (66.7%)

No sleep at all

1 (16.7%)

-

-