Smoking is a well-known risk factor for complications after surgery. Stopping smoking before surgery is likely to reduce the risk of complications. We reviewed the evidence about the effects of providing smoking cessation interventions to people awaiting surgery on their success in quitting at the time of surgery and longer-term, and at complications following surgery. The evidence is current to January 2014.
We searched for randomized studies enrolling people who smoked and were awaiting any type of planned surgery. The trials tested interventions to encourage and help them to stop smoking before surgery. Interventions could include any type of support, including written materials, brief advice, counselling, medications such as nicotine replacement therapy (NRT) or varenicline, and combinations of different methods. The control could be usual care or a less intensive intervention.
We found 13 studies which met the inclusion requirements. The overall quality of evidence was moderate, limited by the small number of studies contributing to key analyses. Participants were awaiting a range of different types of surgery. Interventions differed in their intensity, and in how long before surgery they began. Both brief (seven trials, 1141 participants) and intensive (two trials, 210 participants) behavioural interventions were effective in increasing the proportion of smokers who were not smoking at the time they had surgery. The two trials using intensive interventions which started four to eight weeks before surgery had larger effects. Six trials of behavioural interventions assessed postoperative complications. Both trials of intensive interventions (210 participants) detected a reduction in complications in people receiving intervention, but the combined results of the four trials of brief interventions did not show a significant benefit. Only four trials of behavioural interventions followed up participants at twelve months. The two intensive interventions (209 participants) reduced the number of people smoking but the two brief interventions (341 participants) no longer showed a difference in the number of smokers. One trial of varenicline (286 participants), a pharmacotherapy shown to assist quitting in other groups of smokers, showed a benefit on cessation after twelve months, but did not show a benefit at the time of surgery or affect complications. In this trial smokers were only asked to stop the day before surgery.