Smoking status and 30-day mortality in patients undergoing pulmonary resections

Abstract

Background Smoking status has not been shown to have a significant effect on 30-day mortality after potentially curative resectional surgery for non-small-cell lung cancer, and this is reflected in the guidelines of the National Institute for Health and Care Excellence in the United Kingdom. Methods A validated prospective thoracic surgery database of consecutive patients undergoing potentially curative resection at a single institution was analyzed. Univariate and propensity analyses of 30-day mortality were performed. Results Univariate analysis identified 30-day mortality as significantly lower in current smokers ( n = 852, 2.6%) than ex-smokers ( n = 1587, 4.9%; p < 0.001). Propensity 1:1 matching of male patients resulted in 727 current smokers being matched to 727 ex-smokers. The overall balance test (χ2 = 6.1, degrees of freedom = 8, p = 0.6), indicated a good match. After propensity matching, the mortality rate was significantly higher in current smokers ( p = 0.01). Conclusions Current smokers and ex-smokers are statistically different with regard to risk factors for death. This results in a skewed population of current and ex-smokers undergoing resection for non-small-cell lung cancer. Development of a risk model for 30-day mortality revealed that current smokers have a lower predicted 30-day mortality than ex-smokers, a finding that is counterintuitive. Propensity matching balanced the current and ex-smoker groups to correct for group differences. Analysis after propensity matching identified current smoking as a significant factor determining 30-day mortality.