Int. J. Environ. Res. Public Health 2011, 8 416 non-smoking adults in the household (yes or no), Heaviness of Smoking Index (HSI) (range from 0 to 6) [35], smoke-free home policy (partial/no ban or total ban), smoke-free bar policy (partial/no ban or total ban), smoke-free restaurant policy (partial/no ban or total ban), and smoke-free worksite policy (partial/no ban, total ban, or not employed outside the home). Support for smoking bans in worksites, bars, and restaurants were also assessed using a five level index in which a value of ‘1’ represented the belief that smoking should be allowed in all four of the aforementioned venues types, a value of ‘5’ represented the belief that smoking should be prohibited in all four venue types, and intermediate values representing the belief that smoking should be prohibited in one, two, or three of the venue types. 2.3. Data Analysis Data analyses were conducted using SPSS version 14.0 (SPSS Inc., Chicago, IL). All bivariate analyses were restricted to participants with complete data for the indicator of interest and stratified by both participant smoking status and country of residence. Cross-sectional data were weighted by age, gender, and region [32] to provide representative population estimates for the following four outcomes: total smoking ban in the home, worksite, bars, or restaurants. Bivariate analyses pertaining to cohort data were unweighted and included the following four outcomes: introduction of a smoke-free policy, retention of no total ban, removal of total ban, or retention of a smoke-free policy. For each of the aforementioned bivariate analyses, a chi-square test was used to determine statistically significant differences across subgroups (α = 0.05). A binary logistic regression model was also constructed to identify significant predictors of policy prevalence (total ban vs. partial/no ban at Wave 5), introduction (introduction vs. no introduction at Wave 6 among those with no ban at Wave 5), and removal (removal vs. no removal at Wave 6 among those with a total ban at Wave 5) among current and continuing smokers, while simultaneously adjusting for the effects of the following covariates: SES, age, gender, minority status, country of residence, children less than 18 years of age in the household, non-smoking adults in the household, HSI, attitudes toward smoke-free policies in public places, and the presence of current total smoking bans in local bars, restaurants, and worksites. To verify whether the effects of SES were consistent across countries, a separate model was also constructed that included the aforementioned covariates and a statistical interaction term for SES and country. Due to limited sample size, it was not possible to construct any regression models among former smokers. 3. Results 3.1. Smoke-Free Home Policies Table 1 presents the prevalence, introduction, retention, and removal of smoke-free home policies by SES and country of residence. Overall, the proportion of current smokers who reported that smoking was never allowed anywhere in their home (total ban) was greatest among respondents from Australia (Wave 5: 46.4%; Wave 6: 50.1%) and lowest among those from the UK (Wave 5: 23.9%; Wave 6: 29.4%) at both Waves. Among former smokers, respondents from Australia had the highest proportion of total bans at both Waves (Wave 5: 69.4%; Wave 6: 74.9%), while those from the UK