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

Abstract

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, P < 0.001). 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, P < 0.001). 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.