Association between Smoking and Mortality: Khon Kaen Cohort Study, Thailand


Background: Despite anti-smoking campaigns, smoking prevalence among Thai males aged 30 or older is high,at around 50%. The purpose of this study was to determine the relationship between smoking and mortality ina rural Thai community. Materials and
Methods: Subjects enrolled into the Khon Kaen cohort study between1990 and 2001 were followed up for their vital status until 16th March 2012. The death resource was from theBureau of Policy and Strategy, Ministry of Interior, Thailand. A Cox proportional hazards model was used toanalyse the association between smoking and death, controlling for age, education level and alcohol drinking,and confidence intervals were calculated using the floating risk method.
Results: The study recruited 5,962 malesubjects, of whom 1,396 died during a median 13.5 years of follow-up. Current smokers were more likely todie than never smokers after controlling for age, education level and alcohol drinking (HR, 95%CI: 1.41, 1.32-1.51), and the excess mortality was greatest for lung cancer (HR, 95%CI: 3.51, 2.65-4.66). However, there wasno increased risk with increasing dose of tobacco, and no difference in risk between smokers of yamuan (handrolledcigarettes) and manufactured tobacco.
Conclusion: Mortality from cancer, particularly lung cancer, andfrom all causes combined is dependent on smoking status among men in rural Thailand, but the relative risksare lower than have been reported from studies in high income countries, where the tobacco epidemic is moreestablished.