TABLE 2

Hazard ratios (HR) for the association between determinants and a subsequent asthma exacerbation in 495 participants

DeterminantValueHR univariable (95% CI, p-value)HR model 1 (95% CI, p-value)
Age years (mean±sd)69.3±8.80.98 (0.96–1.00, p=0.048)
Female n (%)345 (69.7)0.97 (0.70–1.33, p=0.842)
Smoking n (%)
 Never164 (33.1)ReferenceReference
 Former288 (58.2)1.17 (0.84–1.63, p=0.348)1.20 (0.84–1.70, p=0.312)
 Current43 (8.7)1.62 (0.94–2.82, p=0.084)1.59 (0.91–2.77, p=0.104)
Smoking by sex interaction(p=0.0023)
Obesity# n (%)
 No319 (64.4)ReferenceReference
 Yes176 (35.6)1.37 (1.01–1.84, p=0.041)1.38 (1.01–1.87, p=0.040)
Previous exacerbation n (%)74 (14.9)4.05 (2.94–5.56, p<0.001)4.25 (3.07–5.90, p<0.001)
R03 medication+ n (%)
 None165 (33.3)Reference
 Rescue35 (7.1)2.82 (1.49–5.37, p=0.002)3.08 (1.61–5.90, p=0.001)
 Controller167 (33.7)2.45 (1.57–3.82, p<0.001)2.50 (1.59–3.92, p<0.001)
 Rescue+Controller128 (25.9)4.50 (2.90–7.00, p<0.001)4.42 (2.82–6.94, p<0.001)
R03 controller to total ratio0.8 (0.3)0.79 (0.50–1.26, p=0.324)0.77 (0.48–1.23, p=0.276)
Respiratory complaints§ n (%)
 Wheezing323 (65.8)2.08 (1.45–2.96, p<0.001)2.07 (1.44–2.97, p<0.001)
 Dyspnoea301 (65.4)2.02 (1.39–2.91, p<0.001)2.18 (1.48–3.21, p<0.001)
 Chronic cough105 (21.2)1.32 (0.95–1.83, p=0.105)1.34 (0.96–1.87, p=0.085)
Lung function n (%)
 Normal359 (76.2)ReferenceReference
 Restriction11 (2.3)1.27 (0.47–3.44, p=0.643)1.20 (0.44–3.27, p=0.722)
 Obstruction101 (21.4)1.57 (1.11–2.20, p=0.010)1.52 (1.07–2.15, p=0.019)
FEV1 % pred (mean±sd)91.2±17.40.98 (0.97–0.99, p<0.001)0.97 (0.97–0.99, p<0.001)
COPD co-diagnosis n (%)48 (9.7)1.45 (0.96–2.21, p=0.080)1.48 (0.97–2.28, p=0.071)
Depressive symptomsƒ n (%)72 (14.7)1.50 (1.02–2.19, p=0.038)1.55 (1.05–2.29, p=0.027)
Diabetes mellitus n (%)44 (9.0)1.18 (0.70–1.97, p=0.530)1.12 (0.66–1.91, p=0.678)
Coronary heart disease n (%)16 (3.3)0.98 (0.44–2.23, p=0.971)1.05 (0.46–2.41, p=0.899)

Univariate and model 1 are age and sex adjusted. FEV1: forced expiratory volume in 1 s. #: body mass index >30; : prior exacerbation in the last 12 months; +: any valid R03 prescription; §: confirmative answer to “did you suffer from wheezing/did you suffer from dyspnoea/did you cough daily for >3 months in the past 2 years?”; ƒ: Center for Epidemiologic Studies Depression scale >16. Bold indicates statistical significance.