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, EMBASE, HEALTHSTAR, PAIS, and CDP File (National Centre for Chronic Disease Prevention and Health Promotion, CDC) "Smoking and Health database". 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 before and after studies and interrupted time series, and uncontrolled before and after studies. 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 the study was abstracted by one reviewer and checked by two others. Studies were combined using qualitative narrative synthesis.

Eleven of 22 studies reporting information about interventions to reduce smoking in public places met all the inclusion criteria. All included studies were uncontrolled before and after studies. The most effective strategies used comprehensive, multicomponent 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, multicomponent strategies effectively reduced smoking within public places. Less comprehensive strategies were less effective. All the studies used relatively weak experimental designs. Most studies were done in the USA, and 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.