Smoking Cessation Reduces Postoperative Complications: A Systematic Review and Meta-analysis
Smoking cessation before any type of surgery reduced risks of complications, including wound healing and pulmonary complications. Longer periods of cessation prior to surgery had a significantly larger reduction in complications.
Abstract
Objective
We aimed to review randomized trials and observational evidence to establish the effect of preoperative smoking cessation on postoperative complications and to determine if there is an optimal cessation period before surgery.
Methods
We conducted a systematic review of all randomized trials evaluating the effect of smoking cessation on postoperative complications and all observational studies evaluating the risk of complications among past smokers compared with current smokers. We searched independently, in duplicate, 10 electronic databases and the bibliographies of relevant reviews. We conducted a meta-analysis of randomized trials using a random effects model and performed a meta-regression to examine the impact of time, in weeks, on the magnitude of effect. For observational studies, we pooled proportions of past smokers in comparison with current smokers.
Results
We included 6 randomized trials and 15 observational studies. We pooled the 6 randomized trials and demonstrated a relative risk reduction of 41% (95% confidence interval [CI], 15-59, P = .01) for prevention of postoperative complications. We found that each week of cessation increases the magnitude of effect by 19%. Trials of at least 4 weeks’ smoking cessation had a significantly larger treatment effect than shorter trials (P = .04). Observational studies demonstrated important effects of smoking cessation on decreasing total complications (relative risk [RR] 0.76, 95% CI, 0.69-0.84, P < .0001, I2 = 15%). This also was observed for reduced wound healing complications (RR 0.73, 95% CI, 0.61-0.87, P = .0006, I2 = 0%) and pulmonary complications (RR 0.81, 95% CI, 0.70-0.93, P = .003, I2 = 7%). Observational studies examining duration of cessation demonstrated that longer periods of cessation, compared with shorter periods, had an average reduction in total complications of 20% (RR 0.80, 95% CI, 3-33, P = .02, I2 = 68%). Conclusion Longer periods of smoking cessation decrease the incidence of postoperative complications. To read this article in its entirety, please visit our website.
— Edward Mills, PhD, MSc, Oghenowede Eyawo, MPH, Ian Lockhart, DLitt et Phil, Steven Kelly, MSc, Ping Wu, MBBS, MSc, Jon O. Ebbert, MD, MS
This article originally appeared in the February 2011 issue of The American Journal of Medicine.
