Table 4 Factors associated with fixed airway obstruction in patients with severe asthma

Smoking more than 5 pack-years

< 0.001

3.8 (2.1-7.0)

0.015

6.6 (1.4-30.1)

Asthma more than 15 years

0.064

1.8 (1.0-3.4)

0.028

5.4 (1.2-24.4)

Absence of rhinosinusitis

0.014

2.0 (1.2-3.4)

0.023

3.8 (1.2-12.3)

Age ≥50 years

< 0.001

3.2 (1.9-5.6)

0.632

1.6 (0.2-10.4)

Onset age < 40 years

0.018

0.5 (0.3-0.9)

0.893

1.1 (0.2-8.2)

Male sex

< 0.001

2.7 (1.6-4.7)

0.907

1.1 (0.3-4.9)

Presence of atopy

0.069

0.5 (0.2-1.1)

0.097

0.4 (0.1-1.2)