Saw Swee Hock School of Public Health, National University of Singapore, 16 Medical Drive, Singapore, Singapore.
Tob Control. 2013 Jul;22(4):235-40. doi: 10.1136/tobaccocontrol-2011-050106. Epub 2011 Dec 14.
This study determines if recent smoking cessation, compared with long-term cessation, can reduce mortality risk associated with smoking.
Data from the Singapore Chinese Health Study, a cohort study of middle-aged and elderly Chinese in Singapore, were analysed (n=48 251). Smoking status was evaluated at recruitment between 1993 and 1998 and reassessed between 1999 and 2004. Participants were classified as never-smokers, long-term quitters (quit before recruitment, mean 17.0 years), new quitters (quit between recruitment and second interview, mean 4.3 years) and current smokers. Mortality was ascertained by linkage with the nationwide death registry.
After a mean follow-up of 8.1 years, 6003 deaths had occurred by 31 December 2009. Compared with current smokers, the adjusted HR (95% CI) for total mortality was 0.84 (0.76 to 0.94) for new quitters, 0.61 (0.56 to 0.67) for long-term quitters and 0.49 (0.46 to 0.53) for never-smokers. New quitters had 24% reduction in lung cancer mortality (HR: 0.76, 95% CI 0.57 to 1.00) and long-term quitters had 56% reduction (HR: 0.44, 95% CI 0.35 to 0.57). Risk for coronary heart disease mortality was reduced in new quitters (HR: 0.84, 95% CI 0.66 to 1.08) and long-term quitters (HR: 0.63, 95% CI 0.52 to 0.77), although the result for new quitters was of borderline significance due to relatively small number of cardiovascular deaths. Risk for chronic pulmonary disease mortality was reduced in long-term quitters but increased in new quitters.
Significant reduction in risk of total mortality, specifically for lung cancer mortality, can be achieved within 5 years of smoking cessation.
本研究旨在探讨与长期戒烟相比，近期戒烟是否可以降低与吸烟相关的死亡风险。
对新加坡华人健康研究（一项针对新加坡中老年华人的队列研究）的数据进行分析（n=48251）。1993 年至 1998 年招募时评估吸烟状况，并于 1999 年至 2004 年进行再次评估。参与者被分为从不吸烟者、长期戒烟者（招募前戒烟，平均 17.0 年）、新戒烟者（招募至第二次访谈期间戒烟，平均 4.3 年）和当前吸烟者。通过与全国死亡登记处的链接确定死亡率。
在平均 8.1 年的随访后，截至 2009 年 12 月 31 日，共发生 6003 例死亡。与当前吸烟者相比，新戒烟者全因死亡率的调整 HR（95%CI）为 0.84（0.76 至 0.94），长期戒烟者为 0.61（0.56 至 0.67），从不吸烟者为 0.49（0.46 至 0.53）。新戒烟者肺癌死亡率降低 24%（HR：0.76，95%CI 0.57 至 1.00），长期戒烟者降低 56%（HR：0.44，95%CI 0.35 至 0.57）。新戒烟者和长期戒烟者的冠心病死亡率均降低（新戒烟者 HR：0.84，95%CI 0.66 至 1.08；长期戒烟者 HR：0.63，95%CI 0.52 至 0.77），但由于心血管疾病死亡人数相对较少，新戒烟者的结果仅为边缘显著。慢性肺部疾病死亡率在长期戒烟者中降低，但在新戒烟者中增加。
戒烟 5 年内，全因死亡率，特别是肺癌死亡率，可显著降低。
