Abstract

Objective: To assess the benefits of smoking cessation regarding mortality reduction after smokers quit, and regarding the health of newborns after smoking mothers quit.

Methods: Relative mortality risks (RR) for smokers aged 35 or older who quit years ago were calculated from the follow up of 71 361 civil servants and teachers recruited since 1989. Data from the Pregnancy Risk Assessment Monitoring System in Taipei City were used to calculate the odds ratios of body weights of newborns born to mothers of different smoking status.

Results: Mortality risk for ex-smokers was significantly lower than that of current smokers for all causes (18%), all cancer (22%), lung cancer (39%), and ischaemic heart disease (54%). These benefits were not distinguishable initially, up to five years, but by year 17 and thereafter, substantial benefits of cessation accrued. Two thirds of smoking women quit during the first trimester of pregnancy, and only 2.2% of mothers smoked throughout pregnancy. The newborns from smoking mothers were smaller than those from never smoking mothers, but, if these mothers quit early in the first trimester, birth weights were normal.

Conclusions: The health benefits of smoking cessation, rarely reported for Asian populations, have been largely ignored by smokers in Taiwan, where cessation activities have been extremely limited. Findings of this study that risks from smoking can be attenuated or reversed should be widely communicated to motivate smokers to quit. Smokers should quit early, including smoking mothers, and not wait till medical conditions surfaced, to have the maximal benefits of cessation.