Smoking As a Risk Factor for Postcraniotomy 30-Day Mortality

BACKGROUND: There is limited information on the impact of smoking on postcraniotomy mortality. In this study we used the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) to examine this issue. METHODS: We identified 16,280 postcraniotomy patients in the ACS-NSQIP database. Indications for surgery were categorized by vascular, trauma, epilepsy, malignant tumor, and benign tumor. Univariate and multivariable logistic regression analyses were used to identify risk factors associated with mortality. RESULTS: In the ACS-NSQIP dataset, postcraniotomy mortality within 30 days of surgery was 5.03%. An area under the curve analysis indicated 30 pack-years as the optimal discriminating threshold for risk stratification in terms of 30-day postcraniotomy mortality. Using this threshold, multivariate analyses revealed 3 variables that were closely associated with 30-day post-craniotomy mortality: male gender (P = 0.002), indication for operation (P< 0.001), and a smoking history of >= 30 pack-years (P < 0.001). In subsequent stratified analyses, smoking-associated mortality risk was observed only in males (odds ratio of 2.33 comparing males with <= 30 and <30 pack-years of smoking history; 97.5% confidence interval 1.36-4.03). When the analysis was further stratified by surgical indications, the mortality association with smoking was found only in male patients who underwent craniotomy as treatment for neurovascular diseases (odds ratio 3.88, 97.5% confidence interval 1.39-11.65). Such an association was not seen in patients who underwent craniotomy for traumatic brain injury, malignant tumors, benign tumors, or epilepsy. CONCLUSIONS: This study identified >= 30 pack-years as a risk factor for male patients undergoing craniotomy as treatment for neurovascular diseases.