Sex Differences for Anterior Cervical Fusion: Complications and Length of Stay

Study design: Retrospective cohort. Objective: To assess differences in baseline characteristics between sexes of patients undergoing anterior cervical discectomy and fusion (ACDF) and risk factors for adverse outcomes according to sex. Summary of background data: ACDF is a common treatment for cervical spine disease. To reduce the rate of complications, risk factors associated with adverse events have been identified. However, few studies have examined the risk for inferior outcomes or complications after ACDF by sex. Methods: The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was used to identify patients who underwent ACDF from 2005 through 2014. Data collected included demographics, comorbidities, operative characteristics, and postoperative adverse events. Demographic and comorbidity variables were compared between men and women using chi-squared analysis. Perioperative outcomes were compared between groups using multivariate linear regression or Poisson regression with robust error variance controlling for preoperative characteristics. Results: In the 20,383 patients who met inclusion criteria, the male cohort was slightly older, less likely to be normal weight or morbidly obese, and had a higher incidence of diabetes and hypertension (P \u3c 0.001 for each). Male sex was associated with a greater risk of any adverse event (relative risk = 1.2; P = 0.043), as well as any severe adverse event (relative risk = 1.4; P = 0.001). Moreover, male sex exhibited longer operative times compared to the female group (127 vs. 117 min; β = 10; P \u3c 0.001). Conclusion: The results of the current study suggest male sex is associated with an increased risk of adverse events following ACDF. Male sex has previously been demonstrated to correlate with medical comorbidities, which may be partly responsible for the increased morbidity. Because of the contrasting evidence throughout the literature, further studies are required to better elucidate this effect