Background:
The workplace appears to be a useful setting for helping people to stop smoking. Large groups of smokers are available who can easily be reached and helped, using proven methods. It is also in the employers’ interests to improve the health of their workforce. Recent changes introducing anti-smoking laws in many developed countries may have eased the pressure to demonstrate the value of work-based programmes. The situation in developing countries still requires that such methods be tested and proved in those communities. We reviewed the evidence about workplace programmes to help employees stop smoking, and any information about their costs and benefits.

Results:
We searched for studies in July 2013, and identified ten new trials that fitted our criteria, making a total for this update of 61 comparisons across 57 included studies. We grouped them into two broad categories: those aimed at helping individual smokers, and those that targeted the workplace environment as a whole. The first group includes such methods as individual or group counselling, self help, nicotine replacement therapy (NRT) and other medications, help from workmates or other staff, and helping quitters to stay smoke-free. The second group includes environmental cues (posters, reminders), financial or material incentives, and comprehensive smoking cessation or health promotion programmes. The review found that programmes based on group behaviour therapy (eight trials; 1309 participants), on individual counselling (eight trials; 3516 participants), on medications (five trials; 1092 participants), and on several interventions combined (six trials; 5018 participants) helped people to stop smoking.

The chances of stopping smoking using these methods are about the same in the workplace as they are in other settings. This review found that the following do not help people to stop smoking when delivered in the workplace: self-help methods, support from friends, family and workmates, relapse prevention programmes, environmental cues, or comprehensive programmes aimed at changing several high-risk behaviours. Results were mixed for incentives, with one high-quality trial finding a clear benefit for incentives while the remaining five did not.

Quality of the evidence:
Earlier studies tended to be less well-conducted and reported than recent ones. Fewer than one in five studies randomized their study population by an acceptable method. Two-thirds of the studies checked the accuracy of those who said they had quit by testing their breath, blood or urine. The results were generally in line with findings from other reviews of those ways of quitting in any setting. The 'Summary of findings' table shows that the trials were generally rated as being of moderate to high quality, further confirming the strength of our findings. Future research might examine what features of the large incentives trial made it more successful than other trials in that group. It would also be helpful to have more trials from developing and low-income countries, where smoking rates remain high and anti-smoking laws are not widely enforced.