Methods We used longitudinal data (1999–2000) from a US national sample of adult smokers (n=6415) from the Current Population Survey, Tobacco Use Supplements. At baseline, smokers were asked whether they made a quit attempt in the past year. They were also asked whether they thought smoking should not be allowed in hospitals, indoor sporting events, indoor shopping malls, indoor work areas, restaurants, or bars and cocktail lounges. At 1-year follow-up, smokers were asked whether they had quit smoking.