[Association between smoking status and mortality risk among elderly people aged 60 and above in Beijing City]

Objective: To examine the association between smoking status and related mortality among elderly people aged 60 and above in urban and rural areas of Beijing City. Methods: Based on Beijing City Elderly Comprehensive Health Cohort Study from 2009 to 2014, a total of 4 499 eligible older adults included in the baseline survey were followed up and investigated to collect information on survival and death. The Cox proportional hazards regression model was used to estimate hazard ratios (HRs) and corresponding 95% confidence intervals (CIs), and the dose-response relationship was estimated between the smoking index, the years of quitting and mortality. Results: The median (IQR) age of 4 499 subjects was 70.00 (10.00) years old, including 1 814 (40.32%) males. The proportion of non-smokers, former smokers and current smokers was 69.50% (3 127/4 499), 13.20% (594/4 499) and 17.30% (778/4 499), respectively. After adjusting for confounding factors such as demographic and sociological characteristics, lifestyle, etc., the results of multivariate Cox regression analysis showed that, compared to non-smokers, former smokers had a 30.6% increased risk of all-cause mortality [HR (95%CI): 1.306 (1.043-1.636)] and the HR (95%CI) of all-cause, malignant tumor and lung cancer mortality among current smokers has increased by 50.0% [HR (95%CI): 1.500 (1.199-1.877)], 80.3% [HR (95%CI): 1.803 (1.226-2.652)] and 212.6% [HR (95%CI): 3.126 (1.626-6.012)], respectively. The smoking index was positively associated with the increased risk of all-cause, malignant tumor and lung cancer mortality, while the years of smoking cessation were negatively associated with that risk (P<0.05). Conclusion: Smoking is associated with tobacco-related mortality among elderly people in Beijing City.