Provider volume and short-term outcomes following surgery for spinal metastases

Abstract

This study aimed to analyze the impact of surgeon and hospital volume on short-term outcomes following surgery for spinal metastases. Data from the Nationwide Inpatient Sample (NIS; 2003-2009) were extracted. Patients who underwent decompression and/or fusion for metastatic spinal tumors were identified via International Classification of Diseases, Ninth Revision codes. Surgeon and hospital volume were evaluated as a continuous variable. Multivariable logistic regression analyses were performed to calculate the adjusted odds ratios (OR) of in-hospital mortality, post-operative complication development, non-routine discharges, prolonged length of stay, and high hospital charges with increasing surgeon and hospital volume. In total 3,069 admissions were examined. The overall in-hospital mortality rate was 4.4% and in-hospital complication rate 29.7%; non-routine discharges occurred in 63.3% of patients. Increasing provider volume was not associated with lower odds of in-hospital mortality. However, increasing surgeon volume was associated with significantly lower odds of developing an in-hospital complication (OR 0.70; 95% confidence interval [CI], 0.58-0.85) and having a non-routine discharge (OR 0.76; 95% CI, 0.66-0.87). Increasing hospital volume was not associated with lower odds of developing a post-operative complication (OR 1.17; 95% CI, 1.00-1.37), but was associated with lower odds of having a non-routine discharge (OR 0.83; 95% CI, 0.73-0.95). Patients operated on by higher volume surgeons were less likely to have a prolonged length of stay (over 14 days); higher hospital volume was associated with increased odds of high hospital charges (over $295,511 USD). In this study utilizing the NIS administrative database, patients with metastatic spinal tumors treated by higher volume surgeons had significantly lower complication rates, were more likely to be discharged home following surgery, and were less likely to have a prolonged length of stay. Increasing hospital volume was associated with lower non-routine discharge rates, but with higher hospital charges. Better outcomes with higher volume surgeons may be a reflection of patient selection, and further research is needed to corroborate our findings.

Keywords: Complications; Hospital volume; Nationwide Inpatient Sample; Outcomes; Provider volume; Spinal metastases; Surgeon volume.