WITHDRAWN: Interventions for preventing tobacco smoking in public places

Environmental tobacco smoke is a health hazard. Reducing exposure to tobacco smoke in public places is a widespread public health goal. There is, however, considerable variation in the extent to which this goal has been achieved in different settings and societies. There is therefore a need to identify effective strategies for reducing tobacco consumption in public places.

To evaluate the effectiveness of interventions to reduce tobacco consumption in public places.

We searched the Tobacco Addiction Review Group trials register, MEDLINE and EMBASE in March 2006. We handsearched a key journal and abstracts from international conferences on tobacco. We checked the bibliographies of identified studies and reviews for additional references.

We considered randomized and controlled trials, controlled and uncontrolled before-and-after studies and interrupted time series. The main outcome of interest was levels and measures of compliance with bans and restrictions. We considered strategies aimed at populations, including education campaigns, written material, non-smoking and warning signs, and comprehensive strategies. We also considered strategies aimed at individual smokers.

Information relating to the characteristics and content of all kinds of interventions, participants, outcomes and methods of each study was abstracted by one reviewer and checked by two others. Studies were combined using qualitative narrative synthesis.

Twenty of 25 studies reporting information about interventions to reduce smoking in public places met all the inclusion criteria. Three were controlled before-and-after studies and 17 were uncontrolled before-and-after studies. The most effective strategies used comprehensive, multi-component approaches to implement policies banning smoking within institutions. Less comprehensive strategies, such as posted warnings and educational material, had a moderate effect. Five studies showed that prompting individual smokers had an immediate effect, but such strategies are unlikely to be acceptable as a public health intervention.

Carefully planned and resourced, multi-component strategies effectively reduced smoking within public places. Less comprehensive strategies were less effective. Most studies were done in the USA and, despite increasing evidence from Europe, there is a need to identify ways in which these strategies can be adopted and used in countries with different attitudes to tobacco use. Future studies should also consider the use of more rigorous experimental designs.