Decreasing Trends of Smoking and Smoking Cessation in Successive Thai Birth Cohorts: Age-period-cohort Analysis from 1991-2007 National Surveys

Background: Many tobacco control policies have been implemented to reduce tobacco use throughout the world including Thailand. This study made use of surveillance data of the past two decades to examine age-period-cohort effects on smoking in Thailand.
Methods: Six nationally representative datasets collected during 1991-2007 were used to determine the prevalence of current smoking, former smoking, and never smoking. Effects of age-period-cohort on current, former, and never smoking were examined using age-period-cohort analysis.
Results: Overall tobacco consumption in Thailand has substantially decreased during the past two decades. However, a sluggish decline of smoking trend has been observed in the last decade. Age-period-cohort models showed significant effects of all three of these component factors on current smoking, former smoking, and never smoking, with the exception of an age effect only on former smoking in females. Age-specific prevalence of current smoking in successive birth cohorts increased with age towards 27 years in males and then fell with age while smoking cessation tended to increase with age. Newer cohorts tended to smoke less but were less likely to quit smoking than those in earlier cohorts.
Conclusions: Although newer cohorts had less susceptibility to smoking, smokers in newer cohorts had lower odds of smoking cessation. Effective smoking cessation methods should be promoted.