A prospective investigation of the impact of smoking bans on tobacco cessation and relapse

Background and objectives-To examine the long term impact of workplace smok ing bans on employee smoking cessation and relapse. Over three years we stu died a total of 1033 current or former smokers (intervention group) employe d in smoke-free hospitals and 816 current or former smokers (comparison gro up) employed in non-smoke-free workplaces. The design of this natural exper iment is a prospective cohort study. We randomly selected both hospitals an d employees from 12 strata based on hospital size and state tobacco regulat ions, and sampled employees in the same communities. Main outcome measures were post-ban quit ratio and relapse rate. Research design-Between groups comparisons were conducted using the Cochran -Mantel-Haenszel statistic for general association, stratified Cox proporti onal hazards models, and the CMH analysis of variance statistic based on ra nks. McNemar's test and the sign test were used to test for changes over ti me within each group. Results-Differences in the post-ban quit ratio were observed between interv ention and comparison groups (p less than or equal to 0.02). For employees whose bans were implemented at least seven years before survey, the post-ba n quit ratio was estimated at 0.256, compared with 0.142 for employees in n on-smoke-free workplaces (p = 0.02). After controlling for a variety of fac tors, time to quit smoking was shorter for the hospital employees (p < 0.00 1), with an overall relative risk of quitting of 2.3. Contrary to expectati ons, relapse rates were similar between the groups. Conclusion-Employees in workplaces with smoking bans have higher rates of s moking cessation than employees where smoking is permitted, but relapse is similar between these two groups of employees. The results of this investig ation have international applicability for policy makers, clinicians, emplo yers, and employees. Countries should review smoking policies in workplaces in light of their own smoking patterns and efforts to deal with environmen tal tobacco smoke.