Table 2 Comparisons between subjects with fixed and non-fixed airways obstruction

Patients (n)

44

32

Age (years)

52.3 ± 18.1

57.4 ± 18.2

NS

Age of asthma onset (years)

32.8 ± 22.9

39.3 ± 21.9

NS

Before 12 years old (%)

34.1

18.8

NS

Before 18 years old (%)

36.4

18.8

NS

Before 40 years old (%)

50.0

50.0

NS

Duration of asthma (years)

19.5 ± 17.6

18.1 ± 13.5

NS

Gender (% Males)

56.8

40.6

NS

Body mass index (kg/m²)

25.2 ± 7.3

25.0 ± 5.5

NS

Serum eosinophils

No. of patients (n)

43

31

Absolute eosinophil count (× 10⁹/L)

0.49 ± 0.73

0.46 ± 0.43

NS

Eosinophil count ≥ 0.4 × 10⁹/L (%)

37.2

51.6

NS

Smoking

Current or past smokers (%)

38.6

15.6

0.029

Smoking history (pack-years)

0 (0–10)

0 (0–0)

0.019

Range: 0-64

Range: 0-30

Comorbidities

Allergic Rhinitis (%)

45.5

53.1

NS

Eczema (%)

100

100

NS

Gastroesophageal reflux disease (%)

15.9

12.5

NS

Obstructive sleep apnea (%)

6.8

0

NS

Anxiety (%)

6.8

0

NS

Depression (%)

2.3

3.1

NS

Aspirin sensitivity (%)

0.0

3.1

NS

Vocal cord dysfunction (%)

2.3

0

NS

Skin prick tests

No. of patients (n)

14

14

Positive results on skin prick test to:

Blomia tropicalis (%)

78.6

92.9

NS

Dermatophagoides pteronyssinus (%)

85.7

85.7

NS

Dermatophagoides farinae (%)

85.7

85.7

NS

Dog (%)

64.3

50.0

NS

Cat (%)

50.0

50.0

NS

Feathers (%)

14.3

21.4

NS

Cockroach (%)

28.6

14.3

NS

Aspergillus (%)

14.3

7.1

NS

No. of allergens which test positive

5 (2.75-6)

4 (3–5.25)

NS

Symptoms, health care use, medications

Asthma Control Test score

20 (16–22)

20 (19–24)

NS

Admissions in the past 2 years

0 (0–0) (n = 42)

0 (0–2) (n = 31)

NS

% admitted in past 2 years

14.3

32.3

NS

Emergency visits in the past 2 years

0 (0–2) (n = 43)

1 (0–2) (n = 31)

NS

% with emergency visits in past 2 years

48.8

58.1

NS

No. of steroid bursts in the past year

1 (0–2)

1 (0–2)

NS

% with steroid bursts in the past year

61.4

71.9

NS

History of near-fatal asthma (%)

4.5

9.4

NS

Medication regimen

2 (2–4)

2 (2–4)

NS

Lung function

PostBDFEV₁ (% predicted)

Range

32-69

71-123

NA

Prebronchodilator FEV₁ (% predicted)

45.1 ± 10.0

68.4 ± 15.9

<0.001

Prebronchodilator FVC (% predicted)

56.8 ± 16.8

74.6 ± 15.1

<0.001

Prebronchodilator FEV₁/FVC (%)

61.3 ± 14.1

70.9 ± 12.0

0.003

Percentage reversibility in FEV₁ (%)

26.8 ± 24.2

25.9 ± 18.6

NS

Reversibility in FEV₁ (ml)

283 ± 222

360 ± 242

NS