Figure 3

Logistic analysis of risk factors for COPD in young people. (A) Univariable logistic analysis of risk factors. (B) Multivariable logistic analysis of risk factors. OR and 95% CI were estimated using sample weights from NHANES. BMI<18.5 was regarded as BMI low. BMI>25 was regarded as BMI high. BMI, body mass index; COPD, chronic obstructive pulmonary disease; NHANES, National Health and Nutrition Examination Survey.