Abstract
Surgical intervention is a standard treatment for severe cervical spondylotic myelopathy (CSM), but postoperative outcomes can vary based on socioeconomic characteristics such as insurance status. The aim of this study was to investigate the influence of insurance on patient-reported outcomes (PROs) at 60 months postoperatively.
In this prospective cohort study, the Spine CORe™ study group analyzed data from the Quality Outcomes Database (QOD) database. Chi-square and Kruskal-Wallis tests were performed to identify the associations between sociodemographic and clinical variables and insurance type. The chi-square test was also used to examine the influence of insurance type on the achievement of minimal clinically important difference (MCID) for each outcome measure. Statistically significant covariates (p < 0.001) were used in a multivariate linear regression model measuring the influence of insurance type on 60-month changes in scores for neck and arm pain numeric rating scale (NRS), Neck Disability Index (NDI), EQ-5D, and modified Japanese Orthopaedic Association (mJOA) scores.
From a dataset of 1085 patients who underwent CSM surgery, 106 patients died during the 5-year follow-up period and 793 had an NDI score at the 5-year follow-up. The follow-up rate was 83% ([793 with NDI + 106 died]/1085 patients). Of the 1085 patients, the authors excluded patients with Veterans Affairs insurance, no insurance, or who were missing baseline PROs, which left 1030 patients with Medicare (n = 408), Medicaid (n = 75), and private (n = 547) insurance with 60-month PROs. Insurance status varied based on demographics and medical comorbidities (each p < 0.05). Medicaid patients had significantly worse scores at baseline and 60 months for arm and neck NRS, NDI, EQ-5D, and mJOA (each p < 0.05). In multivariate analysis after adjustment for relevant covariates, compared with private insurance, only Medicare insurance was associated with lower 60-month EQ-5D scores (β -0.05, 95% CI -0.09 to -0.01; p < 0.05). Otherwise, there was no significant difference in PROs. Medicaid insurance was not significantly associated with differences in any of the outcomes after covariate adjustment compared to private insurance.
Despite having worse baseline scores, patients with Medicaid insurance coverage had similar rates of achievement of MCID compared with those with private insurance. These results suggest that patients with CSM who underwent surgery had improvement in PROs for all insurance types.