The impact of insurance status on outcomes after surgery for spinal metastases

BACKGROUND: Disparities based on insurance status in the American health care system are well established. However, to the authors' knowledge, this is the first study to evaluate variables that may explain differences based on payer type in the outcomes after surgery for spinal metastases. METHODS: Data from the Nationwide Inpatient Sample (2005-2008) were retrospectively extracted. Patients ages 18 to 64 years who underwent surgery for spinal metastases were included. Multivariate logistic regression was performed to calculate the adjusted odds of in-hospital death and the development of a complication for Medicaid recipients and for those without insurance compared with privately insured patients. All analyses were adjusted for differences in patient age, gender, primary tumor histology, socioeconomic status, hospital bed size, and hospital teaching status. RESULTS: A total of 2157 hospital admissions were evaluated. The adjusted odds of in-hospital death were significantly higher for Medicaid recipients (crude rate: 6.5%; odds ratio [OR], 1.79; 95% confidence interval [95% CI], 1.11-2.88 [P =.02]) and uninsured patients (crude rate: 7.7%; OR, 2.15; 95% CI, 1.04-4.46 [P =.04]) compared with privately insured patients (crude rate: 3.8%). Complication rates were also significantly higher for Medicaid recipients (OR, 1.34; 95% CI, 1.04-1.72 [P =.02]). However, after also adjusting for acuity of presentation, the odds of in-hospital death were not significantly different for Medicaid (OR, 1.38; 95% CI, 0.86-2.21 [P =.18]) or uninsured patients (OR, 1.86; 95% CI, 0.90-3.83 [P =.09]); in addition, complication rates did not appear to differ significantly. CONCLUSIONS: This nationwide study suggests that disparities based on insurance status for patients undergoing surgery for spinal metastases may be attributable to a higher acuity of presentation.