Table 3.

Factors Associated with Exacerbations in the Intermediate Group

Exacerbation-Free Survival
Variable	Hazard Ratio (95% CI)	P-value
CV of FENO	6.01 (1.09–29.29)	0.04
Exacerbation Frequency
Variable	Rate Ratio (95% CI)	P-value
CV of FENO	7.76 (2.32–26.15)	0.001

Notes: The hazard ratio was derived from the multivariate Cox proportional hazards model, and the rate ratio was derived from the multivariate Poisson regression model. Both models were adjusted for age, sex, body mass index, pack-years, blood eosinophil count, and FENO at baseline.

Abbreviations: CV, coefficient of variation; FENO, fractional exhaled nitric oxide.