Duration of smoking cessation

Pearson correlation

p value

Actual FEV1

0.535

0.702

Actual FVC

0.388

0.299

Actual PEFR

0.415

0.292

Actual TLC

0.548

0.302

CO exhaled level

−0.419

0.406

Functional defect of FEV1

0.624

0.001*

Functional defect of FVC

0.117

0.461

Functional defect of PEFR

0.100

0.517

Functional defect of TLC

0.183

0.257