Hazard Ratios of Current Smoking and Heavy Smoking by age.

aReference group is never smokersbHeavy smoking defined as smoking uptake prior to age 30 and smoking at least a pack or more (20+ cigarettes) per day. Models were run controlling for sex, race/ethnicity, education, BMI, and age.a. 参照组为从不吸烟者 b. 重度吸烟定义为30岁前起始吸烟，且每日吸烟量不少于1包（即20支及以上）。建模过程中对性别、种族/族裔、教育程度、身体质量指数（BMI）及年龄进行了控制。