Table 1

Summary of findings from the ITC Four Country Survey

Policy (reference)	Findings
Warning labels⁵	Increasing warning label size makes the warning more salient and noticeable for smokers; increases content specific knowledge; and increases the likelihood that smokers think about quitting smoking and quit smoking. Graphic warning labels appear to have a greater impact than text only labels.
Smoke-free^6–⁸	Compliance with comprehensive smoke-free legislation can be achieved when accompanied by pre-implementation campaigns. Comprehensive smoking bans do not cause smokers to shift their smoking behaviour to their homes; instead bans in public places promote voluntary establishment of smoking bans at home. Smoking bans promote quitting behaviour and help smokers to remain abstinent following a quit attempt.
Marketing^9–¹¹	UK’s comprehensive advertising ban significantly reduced smokers’ exposure to pro-tobacco marketing and messages. Introducing controls on labelling reduced smokers’ misperceptions of light and mild cigarettes.
Product regulation^12–¹⁵	The level of tobacco-specific nitrosamines (a potent carcinogen) found in the smoke of leading cigarette brands varied widely across countries. Setting minimum toxin cigarette yields using standard ISO testing is ineffective because tobacco companies respond by increasing filter ventilation, a design change for which smokers compensate by increasing their puff volume.
Tax and price^16,¹⁷	Tax avoidance varies considerably across countries and is more frequent among younger, non-white, male, higher income smokers who smoke more cigarettes per day. The increasing prevalence of roll-your-own cigarettes is also a response to higher cigarette prices. The use of low and untaxed source of cigarettes is associated with a lower likelihood of quitting smoking.
Psychosocial predictors^18–²⁰	Lower socioeconomic status (SES) is associated with lower awareness of the harms of smoking and greater misunderstanding about nicotine. In each of the four countries lower SES was associated with higher levels of nicotine dependence and self-efficacy for quitting. Intention to quit and negative attitudes about smoking are important predictors of making a quit attempt, but degree of nicotine dependence is the main factor that predicts cessation among those who have made a quit attempt.