Int. J. Environ. Res. Public Health 2011, 8 423 and residence in either the US or UK. Predictors of increased odds of introducing a total ban between Waves among continuing smokers were greater support for smoking bans in public venues and residence in the UK, while a predictor of decreased odds was residence in the US. There was no significant interaction observed between SES and country in either regression model, and thus the findings are not presented here. 3.4. Smoke-Free Worksite Policies Table 5 presents the prevalence and introduction of smoke-free worksite policies by country of residence among those employed for wages at the time of interview. Overall, the proportion of current smokers who reported that smoking was not allowed in any indoor area of their worksite (total ban) was greatest among respondents from Canada in Wave 5 (88.2%) and those from the UK, where a national ban on smoking in indoor public areas was implemented between Waves, in Wave 6 (96.1%). The US had the lowest proportion at both Waves (Wave 5: 76.8%; Wave 6: 75.9%). Among former smokers, the proportion of respondents with such a policy in Wave 5 was the greatest in the US (92.7%), but lowest in Wave 6 (83.0%). Following stratification by SES, the proportion of current smokers with a total smoking ban in the worksite increased with increasing SES in Canada and the U.S. in Wave 5, but no significant trends were apparent in Wave 6. In the UK, the proportion of former smokers with a total smoking ban in the worksite increased with increasing SES in Wave 5. Between Waves, the introduction of a total ban among continuing smokers significantly decreased with increasing SES in Canada, the U.S. and the U.K. Table 2 presents the findings of a binary logistic regression analysis to identify predictors of the presence and introduction of total bans on smoking in the worksite. Among all current smokers combined, both those with ‘moderate’ [OR: 1.38, 95% CI: 1.06–1.82] and ‘high’ [OR: 2.23, 95% CI: 1.63–3.04] SES had an increased odds of having a total ban on smoking in the worksite in Wave 5; however, rates of smoke-free policy introduction were comparable by SES with lower point estimates among those with the highest SES compared to those with low SES. Among current smokers from all four countries combined, predictors of increased odds of a total ban in Wave 5 were the presence of a total ban in local bars or restaurants and greater support for smoking bans in public venues, while predictors of decreased odds were male gender and higher HSI. No multivariate association was observed between socioeconomic status and the introduction of a total ban in Wave 6. The only predictor of increased odds of introducing a total ban between Waves among continuing smokers was residence in the UK. There was no significant interaction observed between SES and country in either regression model, and thus the findings are not presented here.