Table 1 Demographic and baseline characteristics of the patients at enrollment

Age, years

42.5 (35.0–57.3)

42.0 (38.0–55.0)

44.0 (31.5–60.5)

0.509

Cough duration, weeks

9.5 ± 1.3

9.6 ± 1.4

9.4 ± 1.2

0.458

Sex

0.649

 Male

39 (37.5%)

18 (35.3%)

21 (39.6%)

 Female

65 (62.5%)

33 (64.7%)

32 (60.4%)

Smoking history

 Former smoker

5 (4.8%)

3 (5.9%)

2 (3.8%)

0.965

 Current smoker

3 (2.9%)

1 (2.0%)

2 (3.8%)

1.000

 Never smoked

96 (92.3%)

47 (92.2%)

49 (92.4%)

1.000

Comorbidity

 Hypertension

17 (16.3%)

6 (11.8%)

11 (20.8%)

0.215

 Diabetes

3 (2.9%)

1 (2.0%)

2 (3.8%)

1.000

 Cardiovascular and

cerebrovascular diseases

3 (2.9%)

0 (0.0%)

3 (5.7%)

0.255

Symptoms

 Dry cough

43 (41.3%)

19 (37.3%)

24 (45.3%)

0.406

 Sputum

61 (58.7%)

32 (62.7%)

29 (54.7%)

0.406

 Dyspnea

50 (48.1%)

28 (54.9%)

22 (41.5%)

0.172

 Wheeze

17 (18.3%)

10 (19.6%)

7 (13.2%)

0.378

 Insomnia

4 (3.8%)

1 (2.0%)

3 (5.7%)

0.638

 Fatigue

10 (9.6%)

6 (11.8%)

4 (7.5%)

0.692

 Dizziness and headache

5 (4.8%)

3 (5.9%)

2 (3.8%)

0.965

 Chest pain

5 (4.8%)

3 (5.9%)

2 (3.8%)

0.965

CET

11.0 (9.0–15.0)

12.0 (9.0–16.0)

10.0 (9.0–13.0)

0.142

Dyspnea mMRC

 0

54 (51.9%)

23 (45.1%)

31 (58.5%)

0.172

 1

 2

27 (26.0%)

14 (13.5%)

15 (29.4%)

7 (13.7%)

12 (22.6%)

7 (13.2%)

0.431

0.938

 3

9 (8.7%)

6 (11.8%)

3 (5.7%)

0.448