Table 2 Predictors of repeated asthma exacerbations

Sex, women

1.17 (0.94–1.46)

–

Age

 15–45

1.00

1.00

 46–69

6.00 (4.67–7.71)**

3.56 (2.64–4.81)**

 ≥ 70

11.2 (7.29–17.2)**

6.30 (3.91–10.1)**

Decade of inclusion

 1974–1979

1.21 (0.76–1.95)

–

 1980–1989

1.10 (0.72–1.68)

–

 1990

1.00

–

Years since symptom debut

1.02 (1.01–1.03)**

1.02 (1.00–1.03)*

Adult-onset^a

1.85 (1.41–2.43)**

1.20 (0.81–1.79)

Ever smoker^b

1.57 (1.19–1.82)**

1.50 (1.20–1.88)*

Pack-years^c

1.03 (1.02–1.04)**

1.03 (1.01–1.04)*

Previous severe exacerbation

0.68 (0.50–0.94)*

1.27 (0.89–1.82)

Daily symptoms

2.49 (1.98–3.12)**

1.56 (1.22–1.99)*

Daily β₂-agonist usage, > 2

2.2 (1.74–2.78)**

1.50 (1.13–1.98)*

ICS prescribed at baseline, any dose

1.37 (1.08–1.73)*

0.93 (0.72–1.19)

Lung function

 FEV₁ pred. < 80%

3.04 (2.41–3.83)**

1.70 (1.29–2.25)*

 FEV₁/FVC ratio, < 70%

2.84 (2.28–3.55) *

1.13 (0.86–1.49)

BD reversibility^d

 < 12%

–

–

 ≥ 12%

1.31 (0.96–1.81)

–

AHR, mg/ml

 < 1

1.00

1.90 (0.99–3.67)

 ≥ 1 to < 2

0.65 (0.44–0.96)*

1.41 (0.72–2.76)

 ≥ 2 to < 8

0.56 (0.43–0.80)*

1.92 (1.02–3.60)*

 ≥ 8

1.01 (0.54–1.89)

1.00

Peakflow variability

 < 20%

1.00

–

 ≥ 20%

0.84 (0.68–1.04)

–

Blood eosinophils, × 10⁹/l

 < 0.09

1.31 (0.84–2.04)

0.98 (0.60–1.59)

 ≥ 0.09 to ≤ 0.4

1.00

1.00

 > 0.4

1.33 (1.08–1.65)*

1.29 (1.03–1.61)*

Total IgE, ≥ 150 IU/l

0.71 (0.57–0.89)*

0.99 (0.77–1.27)

Negative skin prick test, n (%)

0.36 (0.28–0.45)**

1.67 (1.25–2.23)*