Smokefree policies to reduce tobacco use. A systematic review.

In 2001, a systematic review for the Guide to Community Preventive Services identified strong evidence of effectiveness of smoking bans and restrictions in reducing exposure to environ- mental (secondhand) tobacco smoke. As follow-up to that earlier review, the focus here was on the evidence on effectiveness of smokefree policies in reducing tobacco use. Smokefree policies imple- mented by worksites or communities prohibit smoking in workplaces and designated public areas. The conceptual approach was modified for this review; an updated search for evidence was con- ducted; and the available evidence was evaluated. Published articles that met quality criteria and evaluated changes in tobacco-use prevalence or cessation were included in the review. A total of 57 studies were identified in the period 1976 through June 2005 that met criteria to be candidates for review; of these, 37 met study design and quality of execution criteria to qualify for final assessment. Twenty-one studies measured absolute differences in tobacco-use prevalence with a median effect of 3.4 percentage points (interquartile interval: 6.3 to 1.4 percentage points). Eleven studies measured differences in tobacco-use cessation among tobacco users exposed to a smokefree policy compared with tobacco users not exposed to a smokefree policy. The median absolute change was an increase in cessation of 6.4 percentage points (interquartile interval: 1.3 to 7.9 percentage points). The qualifying studies provided sufficient evidence that smokefree policies reduce tobacco use among workers when implemented in worksites or by communities. Finally, a systematic economic review identified four studies that, overall, demonstrated economic benefits from a smokefree workplace policy. Additional research is needed to more fully evaluate the total economic effects of these policies.