Int. J. Environ. Res. Public Health 2011, 8 Variables Low Canada Mod. High All Low Between Waves among Continuing Smokers Introduce smoke-free 16.7 8.1 4.6 8.1 25.0 12.6 12.5 14.8 50.0 36.2 29.8 35.8 21.1 14.3 10.2 Retain smoke-free 83.3 73.8 80.5 77.0 43.8 61.5 70.0 60.8 40.0 61.1 64.3 59.9 71.0 70.9 79.5 Retain smoking 0.0 14.0 13.8 12.2 31.2 25.9 16.2 24.0 10.0 2.7 1.2 3.0 7.9 13.8 8.0 Remove smoke-free 0.0 4.1 1.1 2.7 0.0 0.0 1.3 0.4 0.0 0.0 4.7 1.3 0.0 1.0 2.3 n 36 172 87 295 * 48 135 80 263 * 30 185 84 299 * 38 196 88 a Percentages are based on weighted data. b A national policy prohibiting smoking in all worksites, restaurants, and bars was implemented between Waves 5 and 6 in three of the four countries that comprise the United Kingdom. The fourth country, Scotland, implemented such a policy prior to Wave 5. * Statistically significant variation across groups (χ2, p < 0.05). Table 5. Cont. United States Mod. High Socioeconomic Status United Kingdom b All Low Mod. High All Low Australia Mod. High All 14.0 73.3 11.5 1.2 322 428