Regional Variance in Disability and Quality-of-Life Outcomes After Surgery for Grade I Degenerative Lumbar Spondylolisthesis: A Quality Outcomes Database Analysis

Regional differences in outcomes after spine surgery are poorly understood. We assessed disability and quality-of-life outcomes by geographic region in the United States using the NeuroPoint Alliance Quality Outcomes Database.We queried the prospective Quality Outcomes Database patient registry to identify patients who underwent elective 1- or 2-level lumbar surgery for grade I degenerative spondylolisthesis from July 2014 through June 2016. Primary outcome measures included Oswestry Disability Index (ODI) and EuroQOL-5D (EQ-5D) reported at 24 months postoperatively. Differences in EQ-5D and ODI were compared across geographic regions of the United States (Northeast, Midwest, South, West).We identified 608 patients from 12 centers who underwent surgery. Of these, 517 (85.0%) had ODI data and 492 (80.9%) had EQ-5D data at 24 months. Southern states had the largest representation (304 patients; 5 centers), followed by Northeastern (114 patients; 3 centers), Midwestern (96 patients; 2 centers), and Western (94 patients; 2 centers) states. Baseline ODI scores were significantly different among regions, with the South having the greatest baseline disability burden (Northeast: 40.9 ± 16.9, South: 51.2 ± 15.8, Midwest: 40.9 ± 17.8, West: 45.0 ± 17.1, P0.001). The change in ODI at 24 months postoperatively was significantly different among regions, with the South showing the greatest ODI improvement (Northeast: -21.1 ± 18.2, South: -26.5 ± 20.2, Midwest: -18.2 ± 22.9, West: -21.7 ± 19.6, P0.001). All regions had ≥60% achievement of the minimum clinically important difference in ODI at 24 months postoperatively. No regional differences were observed for EQ-5D.Significant regional variation exists for disability outcomes, but not quality of life, at 24 months after spinal surgery for grade I degenerative spondylolisthesis.