The Impact of Hospital Safety-Net Burden on Survival Outcomes in Oral Cavity Cancer Patients

Abstract

Safety-net hospitals, treating a large proportion of uninsured, Medicaid, or other vulnerable populations, have previously been regarded with achieving inferior patient outcomes. Recent studies, however, have shown non-significant survival differences for rectal, hepatocellular, pancreatic, and esophageal cancer patients being treated at high burden safety-net facilities. In this study, we seek to specifically evaluate patients with oral cavity cancers treated at higher safety-net burden hospitals, because survival outcomes for this particular cancer population have been shown to be stratified by various socioeconomic factors. To date, a robust analysis of survival outcomes and hospital safety-net burden for oral cavity cancer patients has not yet been done. To investigate the relationships between hospital safety-net burden, clinicopathologic characteristics, and overall survival in oral cavity cancer (OCC) patients. From the National Cancer Database, we identified 48,176 OCC patients diagnosed with oral cavity cancer between the years 2004 to 2015. Treatment facilities were defined as no safety-net burden hospitals (NBH), low safety-net burden hospitals (LBH), and high safety-net burden hospitals (HBH) based on percentiles of uninsured/Medicaid patients treated: 0-30%, >30-75%, and >75-100% defines treatment facilities as NBH, LBH, and HBH respectively. Social demographic and clinico-pathological variables assessed were age, distance to treatment facility, time to first treatment, gender, race, Hispanic origin, insurance status, median household income, year of diagnosis, Charlson-Deyo score, location of primary site, AJCC stage, facility type and volume, and treatment modality. Safety-net burden of treatment facilities was used as the primary independent predictor in this analysis and the primary outcome of interest was overall survival. Crude and adjusted hazard ratios (aHR) with 95% confidence intervals (CI) were computed using Cox regression modelling, where clustering of patients within facilities was accounted for using robust sandwich covariance matrix estimates. There were 380 NBH (29.9%), 573 LBH (45.2%), and 316 HBH (24.9%) identified among the 1,269 treatment facilities evaluated for their respective safety-net burden and survival outcomes in oral cavity cancer patients. The median percentage of uninsured/Medicaid patients treated was 23.5% (range 18.6-100%) at HBH, 11.6% (range 1.2-18.5%) at LBH, and 0% (range 0-0%) at NBH. Median follow-up in all surviving patients was 49.0 months. A total of 22,466 deaths were reported, and the overall 5-year survival rate was 53.5% (median survival=69.7 months). Median survival for NBH, LBH and HBH was 68.6, 74.8 and 55.0 months, respectively (p<0.0001). However, compared to NBH and LBH, HBH facilities treated more late-staged cancers, racial and ethnic minorities, and patients of a lower socioeconomic status (SES). Thus, after adjusting for the aforementioned social demographic and clinico-pathological variables, no significant survival difference was noted in LBH (aHR 0.97 95% CI 0.91-1.04, p=0.405) or HBH (aHR 1.05 95% CI 0.98-1.13, p=0.175) when compared to patients treated at NBH facilities. While lower actuarial survival rates are observed in HBH compared to LBH and NBH, these findings may be driven by socioeconomic, and clinicopathologic characteristics. Racial and ethnic minorities are more likely to receive care at HBH. These findings suggest that high burden safety-net hospitals provide vital care to vulnerable populations with oral cavity cancer.