Behavior
Mortality Risk Reduction and Smoking Cessation among Older Population with Long-term Smoking History Shimin Chen* Shimin Chen
Background: There is limited evidence on the benefits of smoking cessation among older populations with long-term smoking history. To quantify the association between smoking cessation and mortality by years since quitting among older populations with long-term smoking history.
Design: Data from Beijing Healthy Aging Cohort Study (BHACS), which was conducted among communities aged over 55 years old at recruitment and collected via questionnaire between July 2009 and September 2015, were utilized in this large representative prospective cohort study of older population. Participants were followed up for all-cause and cancer mortality until March 2021. All the participants from BHACS were included in current analyses. Self-reported smoking status and years since quitting were collected at recruitment, and all-cause mortality was followed up. Cox proportional hazards models were used to examine the association of smoking cessation with mortality.
Results: A total of 11 235 individuals were included, with age at recruitment was 70.35 (7.71) years, 4 930 (43.9%) were males. 3 561 (31.7%) were former smokers, with medians (quartiles) years of smoking 43 (34, 50) years. There were 1 617 (14.4%) deaths among 71 573 person-years of follow-up (872 [17.7%] in males). Compared with never smokers, HR (95%CI) for participants who current smoked was 2.898 (2.092-4.013); quit smoking less than 10 years (medians [quartiles] 4 [1, 7] years) before recruitment was 2.738(1.972-3.802); 10 to 20 years (16 [13, 20] years), 1.807(1.286-2.540); and 20 years or more (30 [25, 37] years), 1.293(0.981-1.705). The risk of all-cause and cancer mortality decreased gradually over years since quitting. Quitting less than 10 years, 10 to 20 years and 20 years or more, former smokers avoided an estimated 8.4%, 57.5% and 84.6% of excess all-cause mortality associated with current smoking, respectively. An association of smoking cessation with decreased mortality existed among former smokers regardless of smoking history.
Conclusions: Current smoking was related with almost triple the mortality risk of never smoking in this study. Smoking cessation, even with long-term smoking history, was related with significant decreases in the relative excess mortality associated with continuing smoking.