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Table 2 Predictors of repeated asthma exacerbations

From: Long-term predictors of severe exacerbations and mortality in a cohort of well-characterised adults with asthma

  Bivariate model
HR (95% CI)
Multivariable model
HR (95% CI)
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-onseta 1.85 (1.41–2.43)** 1.20 (0.81–1.79)
Ever smokerb 1.57 (1.19–1.82)** 1.50 (1.20–1.88)*
Pack-yearsc 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 reversibilityd   
 < 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)*
  1. Results from bivariate and multivariable cox proportional hazards (PWP) model shown as hazard ratio (95% CI)
  2. AHR airway hyperresponsiveness, BD bronchodilator, FEV1 forced expiratory volume in 1 second, FVC forced vital capacity, ICS inhaled corticosteroids, IU International Unit, OCS oral corticosteroids
  3. aAge ≥ 18 years
  4. bCurrent or ex-smoker
  5. cOnly ever-smokers
  6. d46 did not have data
  7. *p-value < 0.05. **p-value < 0.001. Multivariable model: Wald Chi2 = 321 Degrees of freedom = 15. p < 0.0001