Objectives: Only limited data are available regarding smoking and health in later life and, in particular, in the older Chinese population. This paper reports the relationship between smoking and mortality in a Chinese cohort aged 70 years and older.
Setting: A population-based study conducted in Hong Kong.
Participants: A cohort comprising 2030 subjects aged 70 and older were assembled in 1991-1992 and followed for 36 months.
Design: A prospective cohort study.
Measurements: Baseline information regarding smoking status as well as several social and health variables were obtained through face-to-face interview at the respondent's place of residence. The outcome variables were mortality from all causes as well as from cancer and cardiovascular and respiratory diseases. Causes of death were ascertained from death certificates.
Results: The prevalence rates of smoking at baseline were 24.9% in men and 8.2% in women. A total of 534 deaths occurred during the 36-month follow-up period. Of these, 447 were attributable to three main causes: cancer, cardiovascular disease, and respiratory disease. Elevated mortality risks from all causes were observed among both male (RR = 1.4; 95% CI, 0.9-1.9) and female (RR = 1.6; 95% CI, 1.0-2.5) current smokers, but the 95% confidence intervals overlapped. Significant association between current smoking and combined mortality from these three major causes was found in men; it was also found in women after excluding those with these diseases at baseline. More than a 3-fold increased risk of cancer mortality was found in current smokers of both sexes. Although nonsignificant associations were found between former smokers and mortality risks in men, women who were former smokers had increased mortality risks from all causes as well as from cancer and respiratory diseases.
Conclusions: This 3-year prospective study of an older Chinese cohort reveals the impact of smoking on health during later life, especially in women. Smoking cessation, particularly in older men, should be beneficial in reducing mortality. Smoking cessation should begin as early as possible for women.