In Thailand, more than 20 years of tobacco control regulations and laws [1,2], may have contributed, at least in part to decreasing the prevalence of smoking and exposure to secondhand smoke [3]. There has been a reduction in the prevalence of current smoking among men from 59.3% in 1991 to 41.7% in 2007 [3], while the prevalence among women has continued to remain low. However, there does not appear to have been any substantial decrease in prevalence since that time; current smoking among male adults in 2009 still remains relatively high at 40.5% [4].

Sangthong et al. [5] reported that the prevalence of current smoking in Thailand decreased from 1991 to 2004 and subsequently has remained flat. During this period, the rate of decline in the prevalence of manufactured cigarette smoking decreased later in the period. However, the prevalence of roll-your-own (RYO) cigarette smoking has remained flat since 1996. Young et al. [6] compared cigarette smokers in Thailand and in Malaysia in 2005, and found that many factors may play a role in tobacco use including taxation, and socio-cultural and economic factors, which may not act independently. “Economic motives are obviously extremely important, because RYO cigarettes are typically less expensive than FM (factory manufactured, added by the current authors) cigarettes and serve as a “discount” option for smokers” (Young et al. [6]). They also reported that any RYO use was associated with living in rural areas, older average age, lower level of education, being male, not working for pay, greater social acceptability of smoking, and attitudes toward tobacco regulation.

One of the purposes of this study was to provide an update of the information presented by Young et al. [6]. The stability of the findings is important given differences in the time period, sampling strategies and question wording. We were interested in determining whether similar patterns related to the demographic variables emerged after 4 years.

1. What is the prevalence of current tobacco use for males and females by type of cigarettes (manufactured vs RYO)? Do many people use both types of products (dual use)?

2. Are there differences in current use by age, by geographic location, by socio-economic status?

3. Are there differences in knowledge, addiction, and in desire to quit among different groups of users?

From 2008 to 2010, 14 countries, most of them being either low or middle income with a heavy burden of tobacco use and highly populated, conducted the Global Adult Tobacco Survey (GATS) to monitor tobacco use in their countries and the changes driven by policies enacted in those nations [7]. Selected as one of the 14 countries, Thailand conducted GATS in 2009 [8,9]. To ensure useful comparisons across the 14 countries, the survey followed the standard GATS protocol.

The target population was noninstitutionalized residents, in Thailand, aged 15 years or above (defined as adults in the current study), and the sample was a nationally and regionally representative probability sample. A stratified three-stage cluster sampling design was used with the strata being five geographic regions: the Bangkok metropolitan area and the North, Northeast, Central, and South regions of Thailand which were further stratified into urban and rural areas. The sampling frame used was supplied by the National Statistical Office (NSO), derived from Thailand’s National Population and Housing Census 2000 [10]. Primary sampling units (PSUs) were blocks in urban areas and villages in rural areas and were randomly selected, in the first stage, using selection probability proportional to size sampling. In the second stage, 16 and 28 households were randomly chosen from the previously selected urban or rural PSUs, respectively, using simple systematic sampling. In the third stage, a face-to-face screening interview was used at each randomly selected household, in which a list of all eligible individuals in the household was drawn up and one person from the list was randomly selected to participate in the interview, using an algorithm of simple random sampling on the handheld device designed for data collection. If the respondent was not available, the interviewer would schedule another appointment to interview. Three attempts were made before the individual was considered a nonrespondent. If a residence was found to be empty, it was declared to be ineligible; if a selected respondent refused to participate, the individual was considered to be a nonrespondent.

All interviewees were informed that they could stop the survey and the response was confidential. Interviewers were selected by provincial statistical offices (PSO) and were only responsible for their own province, with supervisors from corresponding PSOs. Both interviewers and supervisors had experience on national health related surveys fieldwork. All of them had at least a Bachelor’s degree in education. There were 2 interviewers/supervisors - training sessions using the same trainers with technical support from CDC and WHO experts.

The interview was conducted in the selected household; while other members of the household could be present, they were instructed to remain silent during the interview. No proxy responding was allowed and no incentives were provided for participation. For the questionnaire interview (average duration was 19.1 minutes, SD = 7.6 minutes), the trained interviewers used personal digital assistants (PDAs) to collect data. The fieldwork started on February 1, 2009, and was completed on May 31 of the same year.

The questionnaire included information on demographics (age, gender, education, income); use of smoking tobacco and of smokeless tobacco; cessation attempts and interest in quitting; exposure to secondhand smoke; purchase of cigarettes during the last 30 days; exposure to media that provided information on smoking and health effects; questions about pictorial warning labels on manufactured cigarette packs, and knowledge, attitudes, and perceptions about tobacco use. Some questions were added by the Thailand GATS working group and reviewed by the Thailand GATS expert committee [9]. GATS protocols were approved by the Ethics Committee of the Faculty of Public Health, Mahidol University.

A total of 20,566 people aged 15 and over were surveyed in Bangkok and in the four regions of Thailand: North, Northeast, Central and South. The household-level response rate was 97.9%, the individual-level response rate was 96.2%, and the overall response rate, a product of household response rate and individual response rate, was 94.2%. Each of the four non-Bangkok regions had high response rates, with at least 95.1% overall, at least 98.4% at the household level, and at least 96.2% at the individual level. The response rate in the Bangkok metropolitan area was 94.6% at the household level, 90.0% at the individual level, and 85.1% overall.

In 2009, we found that the prevalence of current smoking among Thai adults was 45.6% for men and 3.1% for women. In all, 18.4% of men and 1.0% of women were current users of manufactured cigarettes only, while 15.8% of men and 1.7% of women were current users of RYO cigarettes only and 11.2% of men and 0.1% of women used both RYO and manufactured cigarettes. Users of manufactured cigarettes were younger and users of RYO were older. RYO smokes were also more likely to live in rural areas. When the demographic variables were controlled, there were no differences between the three groups of smoking either in the percentage who answered all seven questions correctly or in total knowledge score. Respondents who smoked only manufactured cigarettes were more likely than dual users and those who used only RYO to report that they were planning on quitting in the next month. Users of RYO only appear to be more addicted than the other two groups as measured by time to first cigarette. These analyses provide recent estimates than have been reported and present information on knowledge and addiction that has not been reported in earlier work.

While comparisons with other surveys such as that National Cigarette Smoking and Alcohol Drinking Survey and the ITC survey can be made, caution should be exercised in that sampling and question wording differed. However, the findings from this study closely mirror those from Young et al. [6] who found that any RYO use was associated with living in rural areas, older average age, lower level of education, male gender, not being in paid work, slightly lower consumption of cigarettes, higher social acceptability of smoking, and positive attitudes toward tobacco regulation.

The proportion of RYO cigarette smokers is higher in Thailand than in its neighbors, such Vietnam (1.1%) and China (2.3%) [11,12]. As Young et al. [6] noted there are many factors that may play a role in differences in prevalence in different countries including cultural, legislative and economic factors.

One important factor in stimulating the decrease in the prevalence of current smoking in Thailand can be found in the increase in the taxation of manufactured cigarettes [13,14]; the excise tax for manufactured cigarettes has increased from 55% in 1992 to 85% in 2009 [13]. However, the taxation rate for blended shredded tobacco, which is used in RYO cigarettes, has remained as low as 500 Thai Baht (approximately 16.5 U.S. dollars, per kilogram since October 13, 1999), leading to the possibility that some smokers of manufactured cigarettes may have started smoking more RYO cigarettes and reduced or eliminated their smoking of manufactured cigarettes.

Since there were differences noted in rural areas and for those with lower education and income, it may be that more focused education programs should be developed focusing on RYO smoking. Enhancement of health education programs with information on the harmful effects of both types of cigarettes may provide much needed information for smokers.

There are some limitations that should be noted about this survey. Questions on reasons for use of RYO were not included and, therefore, the explanations about economic and cultural facts are speculative. Given that smoking among women does not appear to be acceptable, the estimate of prevalence for women may be subject to some misreporting. Some of the strengths include the rigorous procedures for sampling and interviewing used in GATS Thailand and the high response rate.

Thailand has implemented comprehensive tobacco control interventions, including educational campaigns in the media, legislation to ban smoking in public places, increases in the cigarette excise tax, bans on advertising, and the use of a pictorial warning labels on manufactured cigarettes. Taken together, these legislative measures may have changed social norms and perceptions about tobacco use in Thailand. Meanwhile, lack of comparable policies in the control of RYO cigarettes may be playing a role in the overall prevalence of smoking in Thailand, diluting the success of existing programs.

There are demographic differences among the three groups of male tobacco users. RYO smokers are older and more likely to live in rural areas. There appears to be a need for product targeted cessation and prevention efforts that are directed toward specific population subgroups in Thailand and include information on manufactured and RYO cigarettes. In addition, adoption of tobacco control measures for RYO products similar to those for manufactured cigarettes could be considered.

All authors declare to have no competing interest.

SB and LT supervised the GATS Thailand and critically commented the manuscript. JH provided technical support for the GATS Thailand, analyzed the data and drafted the manuscript. MK, CT and AL contributed to the GATS Thailand operation. HP contributed to the sample design. LA contributed to the data analysis. SA critically reviewed the manuscript. All authors read and approved the final version of the manuscript.

The pre-publication history for this paper can be accessed here:

http://www.biomedcentral.com/1471-2458/13/277/prepub