Impact of facility type and volume in low-grade glioma outcomes

Ping Zhu; Xianglin L Du; Angel I Blanco; Leomar Y Ballester; Nitin Tandon; Mitchel S Berger; Jay-Jiguang Zhu; Yoshua Esquenazi

doi:10.3171/2019.6.JNS19409

Impact of facility type and volume in low-grade glioma outcomes

J Neurosurg. 2019 Sep 27:1-11. doi: 10.3171/2019.6.JNS19409. Online ahead of print.

Authors

Ping Zhu^{1

2}, Xianglin L Du², Angel I Blanco¹, Leomar Y Ballester³, Nitin Tandon¹, Mitchel S Berger⁴, Jay-Jiguang Zhu¹, Yoshua Esquenazi^{1

5}

Affiliations

¹ 1Vivian L. Smith Department of Neurosurgery, McGovern Medical School, University of Texas Health Science Center at Houston.
² 2Department of Epidemiology, Human Genetics, and Environmental Sciences, UTHealth School of Public Health.
³ 3Department of Pathology and Laboratory Medicine, McGovern Medical School, University of Texas Health Science Center at Houston.
⁴ 4Department of Neurological Surgery, University of California, San Francisco, School of Medicine, San Francisco, California.
⁵ 5Center for Precision Health, School of Biomedical Informatics, University of Texas Health Science Center at Houston, Texas; and.

PMID: 31561219
DOI: 10.3171/2019.6.JNS19409

Abstract

Objective: The object of this study was to investigate the impact of facility type (academic center [AC] vs non-AC) and facility volume (high-volume facility [HVF] vs low-volume facility [LVF]) on low-grade glioma (LGG) outcomes.

Methods: This retrospective cohort study included 5539 LGG patients (2004-2014) from the National Cancer Database. Patients were categorized by facility type and volume (non-AC vs AC, HVF vs LVF). An HVF was defined as the top 1% of facilities according to the number of annual cases. Outcomes included overall survival, treatment receipt, and postoperative outcomes. Kaplan-Meier and Cox proportional-hazards models were applied. The Heller explained relative risk was computed to assess the relative importance of each survival predictor.

Results: Significant survival advantages were observed at HVFs (HR 0.67, 95% CI 0.55-0.82, p < 0.001) and ACs (HR 0.84, 95% CI 0.73-0.97, p = 0.015), both prior to and after adjusting for all covariates. Tumor resection was 41% and 26% more likely to be performed at HVFs vs LVFs and ACs vs non-ACs, respectively. Chemotherapy was 40% and 88% more frequently to be utilized at HVFs vs LVFs and ACs vs non-ACs, respectively. Prolonged length of stay (LOS) was decreased by 42% and 24% at HVFs and ACs, respectively. After tumor histology, tumor pattern, and codeletion of 1p19q, facility type and surgical procedure were the most important contributors to survival variance. The main findings remained consistent using propensity score matching and multiple imputation.

Conclusions: This study provides evidence of survival benefits among LGG patients treated at HVFs and ACs. An increased likelihood of undergoing resections, receiving adjuvant therapies, having shorter LOSs, and the multidisciplinary environment typically found at ACs and HVFs are important contributors to the authors' finding.

Keywords: AC = academic center; CRT = chemoradiation; EOR = extent of resection; GTR = gross-total resection; HVF = high-volume facility; LGG = low-grade glioma; LOS = length of stay; LVF = low-volume facility; NCDB = National Cancer Database; National Cancer Database; OS = overall survival; PSM = propensity score matching; RT = radiation therapy; STR = subtotal resection; US = United States; hospital based; low-grade glioma; oncology; overall survival; volume based.