Nearly all the Chinese sample (95.2%) were of Han ethnicity. Other sample
characteristics are shown in table 1. The respondents were overwhelmingly male, and
most smoked only factory-made cigarettes (93.8%).
As in China, the vast majority of Thai sample were male, while the proportion of male
smokers was about 54% in both Australia and the US, reflecting the low smoking
prevalence among women in China and Thailand. Young people aged 18-24 were
notably under-represented in both the Chinese and the Thai samples. The age
compositions of the Australian and American samples were comparable. Due to the
differences in economic development and educational systems across the four
countries, only relative levels of income and education were used. The Thai sample
had more roll-your-own smokers especially compared to China and the USA, and the
Thais also smoked fewer cigarettes per day.