Cost Benefit of Implementation of Risk Stratification Models for Adult Spinal Deformity Surgery

Abstract

Study Design/Setting: Retrospective cohort study. Objective: Assess the extent to which defined risk factors of adverse events are drivers of cost-utility in spinal deformity (ASD) surgery. Methods: ASD patients with 2-year (2Y) data were included. Tertiles were used to define high degrees of frailty, sagittal deformity, blood loss, and surgical time. Cost was calculated using the Pearl Diver registry and cost-utility at 2Y was compared between cohorts based on the number of risk factors present. Statistically significant differences in cost-utility by number of baseline risk factors were determined using ANOVA, followed by a generalized linear model, adjusting for clinical site and surgeon, to assess the effects of increasing risk score on overall cost-utility. Results: By 2 years, 31% experienced a major complication and 23% underwent reoperation. Patients with ≤2 risk factors had significantly less major complications. Patients with 2 risk factors improved the most from baseline to 2Y in ODI. Average cost increased by $8234 per risk factor (R2 =.981). Cost-per-QALY at 2Y increased by $122,650 per risk factor (R2 =.794). Adjusted generalized linear model demonstrated a significant trend between increasing risk score and increasing cost-utility (r2 =.408, P