Cigarette smoking and sick leave in an industrial population in Shanghai, China

A study of cigarette smoking and sick leave was conducted at a large petrochemical complex in Shanghai, China in 1988. Among a random sample of 1856 men the smoking prevalence was 80% with the highest rate (84%) occurring in the age group 25-34 years. Only 53% of smokers and 76% of nonsmokers said they believed smoking was harmful to health and knowledge of which diseases were associated with smoking was poor. Retrospective data were also collected on sick leave in 1986 and 1987. In 1986 13% of men took sick leave and in 1987 12%; the mean duration of sick leave was 3 days per year. In 1986 the odds ratios (OR) for taking sick leave were 2.37 for heavy smokers and 1.45 for light smokers compared to unity for nonsmokers; the corresponding OR for 1987 were 1.70 and 1.28 for heavy and light smokers compared with nonsmokers. Smoking was positively associated with sick leave even after adjustment for age, consumption of alcohol and exposure to chemicals; OR = 1.56 (95% confidence interval (Cl): 1.06-2.31) in 1986 and OR = 1.32 (95% Cl: 0.90-1.95) in 1987. Demonstration of this association even in a young population with low sick leave rates illustrates yet again the adverse effects of smoking on health and the urgent need to reduce the very high prevalence of smoking in China.