Is smoking associated with patient reported surgical-site infection after fusion surgery in the lumbar spine?

Abstract

Introduction: Surgical site infection (SSI) is one of the most common complications in patients undergoing spine surgery. Associations between smoking and SSI have been found in previous studies, but with ambiguous results. This study was designed to compare the postoperative rate of SSI among smokers and non-smokers after fusion surgery in the lumbar spine and evaluate risk factors for SSI. Methods and materials: This observational study includes 2546 patients from the Norwegian Registry for Spine Surgery (NORspine), operated with arthrodesis (fusion) surgery for degenerative disorders of the lumbar spine. Data were collected prospectively from the date of operation (baseline) and at 3 months of follow-up. The primary outcome was surgical site infection, reported by the patient responding to a standardized questionnaire. Results: A total of 5.9% of the patients reported a SSI within three months after surgery. No association between smoking and SSI was found. ASA grade>2 (OR 2.07, 95%CI= 1.19-3.60, p= 0.01), lower age (OR 0.98, 95%CI=0.96-0.99 p<0.01) and days of hospital stay (OR 1.09, 95%CI=1.04-1.13, p< 0.001) were identified as independent risk factors for SSI. After stratifying the data on days of hospital stay (<10 days or >9 days), only ASA grade >2 were significant for both groups. For the ones that stayed less than 10 days at the hospital also lower age (OR= 0.98, 95%CI=0.96-0.94, p=<0.01) and previously operated in the back (1.74, 95%CI= 1.13-2.69, p=0.01) were independent risk factors. The risk of developing a SSI increased 1.7 fold with a hospital stay of 10 days or more. Conclusions: The rate of postoperative SSI in this study is in line with previous literature. No increased risk of SSI between smokers and non-smokers were found.