The relative risks of death from lung cancer, death from COPD, and death from any cause among current smokers, as compared with those who had never smoked, increased according to the number of cigarettes smoked per day and the number of years of smoking during all three periods, although the relationships were less consistent for the cardiovascular end points (Tables S3, S4, and S5 in the Supplementary Appendix). Differences in these variables reported at the start of follow-up did not explain the increases from the 1980s (CPS II) to the contemporary period in rates of death from lung cancer and COPD among female smokers and the rate of death from COPD among male smokers. Even within each stratum of smoking intensity and duration, the relative-risk estimates increased over time.
