Provider Volume Impacts Neurosurgical Procedure Selection in Older Patients With High-Grade Glioma

We examined the association between academic center status and neurosurgical resection volume with surgical procedures performed and subsequent survival.

In a population-based study using the Surveillance, Epidemiology, and End Results (SEER)-Medicare-linked databases, we identified patients > 65 years diagnosed with primary WHO grade III-IV glioma from 2008 to 2017. Surgical procedures were identified through Medicare claims from 2007 to 2019. Associations between center type (academic vs. not) and center volume (top 10% of distribution of resections during the study period vs. the bottom 90%) were estimated with upfront surgery procedure (resection vs. biopsy vs. none) and survival by estimating hazard ratios (HRs) and 95% confidence intervals (CIs) from multivariable regression models accounting for within-center provider cluster correlation.

We identified 8592 patients, of whom 8128 could both be attributed to a provider and received neurosurgical intervention attributed to resection or biopsy. When considered together, center volume, not center academic status, drove surgical decisions for first procedure type such that patients treated by a top 10% volume center were 23% more likely to receive resection (95% CI: 14%-34%, p < 0.0001). When considered together, resection, not center volume, drove improvement in overall survival such that patients who received resection, regardless of center volume, were 22% less likely to die during the study period (95% CI: 17%-27%, p < 0.0001).

We provide the first population-based evidence that older patients diagnosed with grade III-IV glioma who seek treatment from higher-volume centers are more likely to receive aggressive neurosurgical care. Aggressive neurosurgical care, even if received from low-volume centers, improves survival.