The efficacy of smoking ban policy at the workplace on secondhand smoking: systematic review and meta-analysis.

Exposure to secondhand smoke (SHS) in the workplace has led many workplaces to set up smoke-free policies to protect non-smoking employees. Although smoke-free workplaces are pervasive, the intensity of the practice is questionable. The purpose of this review is to identify the pooled prevalence estimate of secondhand smoke at smoke-free workplaces and the factors associated with SHS exposure at the workplace despite existing smoke-free policies. Fourteen studies (total 7458 employees) were identified from Pubmed, ScienceDirect, Cinahl, Scopus, and Web of Science from inception to December 2017. Results indicate that despite the existence of smoke-free policies at the workplace, 14 studies reported exposure to secondhand smoke. The pooled prevalence of the SHS exposure was 0.29 (95% CI = 0.23 to 0.36) (P < 0.001). Male young adults working in the hospitality industry are likely to report exposure to secondhand smoke at the smoke-free workplace. While most of the selected studies show the exposure of SHS within the smoking ban workplace, only two studies reported no exposure to secondhand smoke after implementation of smoke-free policies. Although the smoking ban policy at the workplace has been introduced, there are still a number of employees being affected by secondhand smoke. This indicates that there is still a gap of knowledge, attitude, and practice of non-smokers in strengthening the smoke-free policy at the workplace.