title: Association between cigarette smoking history and mortality in 36,446 health examinees in Korea.
abstract: BACKGROUND
  It is well known that smoking is a preventable factor for all-cause mortality; however, it is still questionable how many years after smoking cessation that people will have reduced risk for mortality, in particular in those with a high interest in their own health. We aimed to examine the association between time since quitting smoking and total mortality among past-smokers relative to current smokers.
  
  
  METHODS
  We enrolled 36,446 health examinees that voluntarily taken with diverse health check-up packages of high cost burden in 1995-2003 and followed them till death by 2004. The history of cigarette smoking consumption was collected using a self-administrative questionnaire at the first visit time. Mortality risk by smoking cessation years was analyzed using Cox's proportional hazard model.
  
  
  RESULTS
  Compared to non-smokers, male smokers over 15 pack-years had higher risk for total mortality (HR=1.49, 95%CI 1.02-2.18). The mortality risk in female smokers with same pack-years was more pronounced than that in male smokers (HR=2.83, 95%CI 1.17-7.04) despite a small number of cases. Compared to current smokers, a decrease of total mortality was observed among those who ceased smoking, and inverse dose-response was found with years after cessation: RR 0.98 (95%CI, 0.64-1.41) (<2 yrs), 0.60 (95%CI, 0.43-0.83) (3-9 yrs), and 0.58 (95%CI, 0.43-0.79) (≥10 yrs).
  
  
  CONCLUSIONS
  A reduced risk of total mortality was observed after 3 years of smoking cessation. Our findings suggest that at least 3 years of smoking cessation may contribute to reduce premature mortality among Asian men.
authors: Department of Family Medicine, Inje University Seoul Paik Hospital, Seoul, Korea E-mail : kyyoo@snu.ac.kr.
authors: Kyoungwoo
authors: K
authors: Kim
authors: Taiwoo
authors: T
authors: Yoo
authors: Yeonju
authors: Y
authors: Kim
authors: Ji-ho
authors: JH
authors: Choi
authors: Seung-Kwon
authors: SK
authors: Myung
authors: Sang-Min
authors: SM
authors: Park
authors: Yun-Chul
authors: YC
authors: Hong
authors: Belong
authors: B
authors: Cho
authors: Sue K
authors: SK
authors: Park
authors: Keun-Young
authors: KY
authors: Yoo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D056910:Republic of Korea; D012907:Smoking / Q000401:mortality*; D016540:Smoking Cessation; D011795:Surveys and Questionnaires; D014029:Tobacco Use Disorder / Q000401:mortality*; D055815:Young Adult