Volume-Outcome Relationship in Surgical Interventions for Spinal Metastases.

Abstract

Surgery for spinal metastases is challenging and carries a high risk of perioperative morbidity and mortality. Procedures with such characteristics often exhibit a volume-outcome relationship. This has not been previously characterized for spinal metastasis surgery to our knowledge. The Florida State Inpatient Database (2011 through 2014) was queried to identify patients who had undergone surgery for spinal metastases. Surgeon and hospital surgical volumes were compared with 90-day complication and readmission rates to develop procedural cut-points used to define high and low-volume providers. These were included in a multivariable logistic regression analysis that was adjusted for confounders. A separate analysis was performed to evaluate the effect of race/ethnicity and insurance status on the likelihood of receiving care from a high-volume surgeon or hospital. This study included 3,135 patients treated by 1,488 surgeons at 162 hospitals. Patients treated at low-volume hospitals had significantly higher odds of having postoperative complications (odds ratio [OR] = 1.47; 95% confidence interval [CI] = 1.13, 1.91) and readmissions (OR = 1.36; 95% CI = 1.06, 1.75). Those treated by low-volume surgeons also demonstrated a higher likelihood of complications (OR = 1.40; 95% CI = 1.16, 1.69) and readmissions (OR = 1.38; 95% CI = 1.17, 1.62). The likelihood of receiving intervention from a high-volume surgeon was significantly lower for African Americans (OR = 0.55; 95% CI = 0.41, 0.75) and Hispanics (OR = 0.60; 95% CI = 0.44, 0.83). The odds of being treated at a high-volume hospital were also significantly lower for African Americans (OR = 0.58; 95% CI = 0.40, 0.84) and Hispanics (OR = 0.28; 95% CI = 0.20, 0.38). There is a clear relationship between the volume and outcomes of surgical treatment of spinal metastases, with high-volume providers demonstrating reduced complication and readmission rates. Racial and ethnic minorities appear to experience health-care segregation when it comes to surgical care for spinal metastases. Regionalization of care for these conditions may help improve access to high-volume providers and mitigate disparities in care. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.