A Cochrane review (abstract , review ) included 57 studies (61 interventions). 31 studies of workplace interventions aimed at individual workers, covering group therapy, individual counselling, self-help materials, nicotine replacement therapy and social support. Group programmes (odds ratio (OR) for cessation 1.71, 95% CI 1.05 to 2.80; 8 trials, n=1309), individual counselling (OR 1.96, 95% CI 1.51 to 2.54; 8 trials, n=3516) and pharmacotherapies (OR 1.98, 95% CI 1.26 to 3.11; 5 trials, n=1092) increased cessation rates in comparison to no treatment or minimal intervention controls. Self-help materials were less effective. There was a lack of evidence that comprehensive programmes applied to the workplace as a whole reduced the prevalence of smoking. Incentive schemes increased attempts to stop smoking, though there was less evidence that they increased the rate of actual quitting.