Smoking in Thailand : a comparison of a large national sentinel cohort to the Thai population and projected future mortality

Abstract

This Thesis focuses on the public health problem of smoking in Thailand. It analyses smoking patterns among adult open-university students and compares them with the pattern in the general Thai population. Smoking and implications for the future burden of disease and the opportunity for effective interventions are addressed. Smoking rates among the open-university students were estimated from a questionnaire administered to a large national cohort of students enrolled at Sukhothai Thammathirat Open University (STOU) in 2005. In the general Thai population smoking patterns were derived from the Third National Health Examination Survey (NHESIII) conducted nationwide in Thailand in 2004. Among the 80,543 open-university students aged 15-60 years at the time of the survey, 21.2 percent of male students and around 1.0 percent of female students reported currently smoking. Around 4.5 percent of female but 34.8 percent of male students were former smokers. The proportion of former male smokers increased with age; more older respondents had quit smoking than younger ones. Most students started smoking at school age. More recent birth cohorts on average started smoking at an earlier age than the older birth cohorts. Surprisingly, the study found a negative relation between starting smoking at school age and parents' education. The higher the education level of the parents, the higher the rate of starting smoking at school age. Smoking behaviour among the open-university students was then compared to that of the national Thai population using data from the Third National Health Examination Survey (NHESIII). A total of 20,555 individuals of the population aged 15-60 years under the NHESIII were covered in the comparison. Both samples have a very similar geographic distribution with the exception that the open-university students had a higher proportion from Bangkok. The students however had higher levels of education, lower marriage rates and slightly higher incomes than the general population. After adjusting for personal income, marital status and geographic region the male national population had 1.6 times higher smoking rates than the open-university students, and the female national population had 1.2 times higher rates. Both the male and female national population groups also smoked more than the students in all education categories except for the female population with a university degree who smoked slightly less than the female open-university students. The Thesis also gives an estimation of the cumulative future healthy life years lost due to morbidity (years lived with disability or YLD) and pre-mature mortality (years of life lost or YLL) attributable to smoking. Expected morbidity and mortality associated with 10 smoking-related diseases were applied to the Thai data at hand using burden of disease techniques assuming present smoking rates continued. It was found that a 25 year old male smoker would lose 11.8 years due to premature mortality or if he quit smoking, he would gain 9.9 years. A 25 year old female smoker would lose 7.6 years due to premature mortality or like a male smoker, she would gain 7.5 years if she quit smoking. In addition, the same male smoker would lose 0.8 healthy years due to smoking related diseases and the same female smoker would lose 1.8 healthy years. Among 25-29 year old male smokers in the student cohort, with this projection, a total loss of 25,477 healthy years due to premature mortality caused by smoking could be expected. In addition, a total loss of 1,072 healthy years could be expected among student female smokers of the same ages. In the past two decades a reduction in smoking prevalence has been observed in Thailand. Accordingly, based on actual decreases in smoking rates in the past 15 years and the effects of cigarette excise taxes on reducing smoking rates, the Thesis projected falling smoking prevalences and total healthy life years lost due to smoking. Findings from this comparison of smoking behaviour reveal the powerful association between education and lower rates of smoking, after adjusting for other factors, thus supporting the potential role of education in reducing smoking rates in Thailand. The findings also provide the STOU and other tertiary institutions with useful information on smoking behaviour among their students.thus assisting with awareness raising measures regarding health risk behaviours among both non smokers and current smokers. Smoking prevalence is still high in Thailand despite the nation-wide implementation of tobacco control policies. So, further research is needed. For example, the baseline questionnaire used here should be repeated in order to measure changes in smoking behaviour over time and examine reasons for the change. The repeated survey should, in addition to repeating the same questions, cover additional issues. Topics of special interest include the behavioural and psychological condition of smokers and non-smokers, reasons for smoking initiation and cessation and non-initiation, attitude toward smoking, perception of smoking effects on health and types of tobacco smoked. Show more