Table 3. Multivariate analysis of risk factors for the severity of asthma exacerbation (mild or moderate vs. severe or life-threatening).

Factors	OR	95% CI	P value
Age (yr)	0.998	0.992–1.005	0.58
Sex	0.929	0.746–1.156	0.51
Disease course (yr)	1.006	1.000–1.012	0.07
Smoking history	1.538	1.205–1.962	< 0.01
History of hospitalization or emergency care visit for asthma in the past year	1.123	0.941–1.339	0.20
Hypertension	1.437	1.163–1.775	< 0.01
COPD	1.601	1.256–2.039	< 0.01
Food allergy	2.231	1.221–4.075	0.01

OR, odds ratio; CI, confidence interval; COPD, chronic obstructive pulmonary disease.