Table 6: Multiple regression analysis FEV1/FVC ratio.

Whole group ( ) (Adj = 0.074)
Regression coefficient95% CI value

Eosinophils (%)−0.113−1.247–−0.1180.018
Use of inhalation corticosteroids−0.025−3.635–2.1220.606
Pack years−0.259−0.162–−0.076<0.001

Variables associated with FEV1/FVC ratio in univariate analysis at a value of <0.1 were examined in the multiple linear regression analysis. Since the FEV1/FVC ratio as percentage predicted is already corrected for height, age, and gender, we did not add this variable to the model. As eosinophils and abdominal circumference are correlated, we selected only one variable to prevent colinearity. We omitted OSAS because of the large proportion of missing data.