Seven RCTs (n=870) were included in the review. Sample sizes ranged from 47 to 237 patients. Randomisation procedure and eligibility criteria were clearly specified in six studies. Comparison data were provided for all studies.
All studies showed that smoking cessation programmes were effective in terms of numbers of patients who were abstinent before surgery. Studies that included counselling in addition to nicotine replacement therapy showed greater benefits. Statistically significant differences were reported between intervention group proportions (range 18% to 93% with a mean of 55%) compared to those in the control groups (range 2% to 65%, mean 27.7%). Two studies reported follow-up rates at six months, at which point no statistically significant differences were reported between intervention and control groups.