A Population-Based Study of Patients with Sleep-Wake Disorders Undergoing Elective Instrumented Spinal Surgery

Background Sleep-wake disorders (SWDs) are associated with multiple systemic pathologies; however, the clinical risk that such disorders carry for spinal surgery patients is not well understood. In the present population-based study, we comprehensively evaluated the significance of sleep-related risk factors on instrumented spinal surgery outcomes. Methods National Inpatient Sample data for the hospitalization of patients who had undergone elective instrumented spine surgery from 2008 to 2014 were analyzed using national estimates. The cohorts were defined as those admissions with or without a coexisting SWD diagnosis identified by International Classification of Diseases, ninth revision, codes. Postoperative complications, mortality rate, length of stay, discharge status, and the total cost of admission were compared between the groups using bivariate and multivariate analyses. Results A coexisting SWD was present in 234,640 of 2,171,167 instrumented spinal surgery hospitalizations (10.8%). Multivariate binary logistic regression accounting for these variables confirmed that a SWD is a significant risk factor for postoperative complications (odds ratio [OR], 1.160; 95% confidence interval [CI], 1.140–1.179; P < 0.0001), length of stay greater than the 75th percentile (OR, 1.303; 95% CI, 1.288–1.320; P < 0.0001), nonroutine discharge (OR, 1.147; 95% CI, 1.131–1.163; P < 0.0001), and death (OR, 1.533; 95% CI, 1.131–2.078; P < 0.01), but not for total charges greater than the 75th percentile (OR, 0.975; 95% CI, 0.962–0.989; P < 0.001). Conclusions SWDs confer an increased risk of morbidity and mortality for elective instrumented spine surgery. Understanding the specific contributions of SWDs to postoperative morbidity and mortality will help physicians implement prophylactic measures to reduce complications and improve postoperative patient recovery.