Association of Insurance Type and Hospital Outcomes Following Posterior Spinal Fusion for Adolescent Idiopathic Scoliosis

Introduction: Insurance type can have a profound impact on patient health. Few prior studies have assessed the association between insurance type and hospital outcomes following spine surgery. The aim of this study was to assess associations between insurance type and length of hospital stay (LOS) and admission costs following posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS).

Methods: A retrospective cohort study was performed using the 2016–2019 National Inpatient Sample (NIS) database. All adolescent patients (ages 10–17) undergoing PSF for AIS, identified using ICD-10 coding, were stratified by insurance type into Medicaid and private insurance (PI) cohorts. Patient demographics, treating hospital characteristics, comorbidities, operative variables, adverse events (AEs), LOS, discharge disposition, and admission costs were assessed. Logistic multivariate regression analyses were performed to identify associations between insurance type and extended LOS and exorbitant costs.

Results: Of the 12,575 study patients, 36.2% (n=4,555) held Medicaid while 63.8% (n=8,020) were privately insured. The Medicaid cohort was younger (p < 0.001) and had a significantly greater proportion of Black- (p < 0.001) and Hispanic-identifying patients (p < 0.001). The overall number of comorbidities was similar between the cohorts (p=0.086). The proportions of patients who experienced any AE (p=0.105) or one or more AEs (p=0.220) were also similar between the cohorts. There were no differences in mean LOS (p=0.055) or in the proportion of patients with non-routine discharges (p=0.939) between cohorts. The Medicaid cohort incurred significantly greater mean admission costs (p=0.023). On multivariate analysis, there were no significant associations between insurance type and extended LOS [aOR: 0.85, CI (0.69, 1.04), p=0.106] or between insurance type and exorbitant costs [aOR: 0.97, CI (0.75, 1.25), p=0.794].

Conclusion : Our study found that insurance type may not significantly influence outcomes in patients undergoing PSF for AIS. Further studies assessing potential patient- and hospital-level drivers of these adverse outcomes are needed.