Early Patient-Reported Outcomes Predict 3-Year Outcomes in Operatively Treated Patients with Adult Spinal Deformity

Background For patients with adult spinal deformity (ASD), surgical treatment may improve their health-related quality of life. This study investigates when the greatest improvement in outcomes occurs and whether incremental improvements in patient-reported outcomes during the first postoperative year predict outcomes at 3 years. Methods Using a multicenter registry, we identified 84 adults with ASD treated surgically from 2008 to 2012 with complete 3-year follow-up. Pairwise t tests and multivariate regression were used for analysis. Significance was set at P < 0.01. Results Mean Oswestry Disability Index (ODI) and Scoliosis Research Society-22r total (SRS-22r) scores improved by 13 and 0.8 points, respectively, from preoperatively to 3 years (both P < 0.001). From preoperatively to 6 weeks postoperatively, ODI scores worsened by 5 points (P = 0.049) and SRS-22r scores improved by 0.3 points (P < 0.001). Between 6 weeks and 1 year, ODI and SRS-22r scores improved by 19 and 0.5 points, respectively (both P < 0.001). Incremental improvements during the first postoperative year predicted 3-year outcomes in ODI and SRS-22r scores (adjusted R² = 0.52 and 0.42, respectively). There were no significant differences in the measured or predicted 3-year ODI (P = 0.991) or SRS-22r scores (P = 0.986). Conclusions In surgically treated patients with ASD, the greatest improvements in outcomes occurred between 6 weeks and 1 year postoperatively. A model with incremental improvements from baseline to 6 weeks and from 6 weeks to 1 year can be used to predict ODI and SRS-22r scores at 3 years.