Sleep Dysfunction and Factors Associated with Improved Sleep in Patients Undergoing Surgery for Degenerative Spondylolisthesis: A Quality Outcomes Database Study

Introduction: Among patients with low-grade degenerative spondylolisthesis, surgery has been shown to relieve pain and improve mobility. Whether durable improvements in sleep dysfunction also occur after surgery is not known.

Methods: The objective was to characterize the prevalence of sleep dysfunction and identify factors associated with improved sleep among patients undergoing surgery for low-grade degenerative spondylolisthesis. 457 patients from the multicenter Quality Outcomes Database were analyzed. Sleep dysfunction was extracted from the Oswestry Disability Index (ODI) and compared at baseline and 24 months.

Results: Three hundred ninety-one patients (85.6%) reported sleep dysfunction at baseline. At 24 months, 275 of the 391 (70.3%) with baseline dysfunction reported improvements in sleep. Patients with baseline dysfunction were more likely to be younger (62.5 vs 67.2 years, p< 0.001), privately insured (54.5% vs 34.8%, p=0.005), and report greater back pain (6.8 vs 5.0, p< 0.001). Although sleep dysfunction was associated with longer hospital stays (2.9 vs. 2.2 days, p=0.003), patients with baseline dysfunction had greater improvements in ODI (-23.8 vs -18.7, p=0.45) and back pain (-3.6 vs -2.7, p=.03). Improved sleep was also associated with fewer reoperations (4.0% vs 12.9%, p=0.003) and global improvements in standardized outcomes. Among patients who underwent fusion, improvement in sleep was predicted by higher baseline ODI (OR=1.02, 95% CI [1.00-1.04], p=0.04), the presence of a baseline motor deficit (OR=2.48, 95% CI [1.14-6.04], p=0.03), and the use of minimally-invasive techniques (OR=1.82, 95% CI [1.04-3.27], p=0.04). Among patients who underwent decompression only, improvement in sleep was predicted by the presence of baseline leg pain (OR=2.93, 95% CI [1.10-8.17], p=0.03).

Conclusion : Most patients (85.6%) presenting for surgery for low-grade degenerative spondylolisthesis have impaired sleep. However, 24 months after surgery, over 70% of patients with baseline dysfunction reported improvements. Improvements are more likely to occur in patients with greater baseline disability and are associated with fewer reoperations.