Association between interhospital transfer and increased in-hospital mortality in patients with spinal epidural abscesses.

BACKGROUND CONTEXT: Spinal epidural abscess (SEA) is an uncommon yet serious infection, associated with significant morbidity and mortality. Patients diagnosed with SEA often require surgical interventions or critical care services that are not available at community hospitals and are therefore transferred to tertiary care centers. Little is known about the effects of interhospital transfer on acute outcomes for patients with SEA. PURPOSE: To study the effects of interhospital transfer on acute outcomes for patients with SEA. STUDY DESIGN: Cross sectional analysis using the 2009 to 2017 National Inpatient Sample (NIS). PATIENT SAMPLE: Using the 2009 to 2017 NIS, we identified cases of SEA using ICD, Ninth, or Tenth Revision diagnosis codes 324.1 & G06.1. OUTCOME MEASURES: Our primary endpoint was in hospital mortality. METHODS: The association between interhospital transfer and inpatient mortality was assessed using multivariable logistic regression to adjust for potential covariates. Patient and hospital factors associated with interhospital transfer were assessed in a secondary analysis. RESULTS: A total of 21.5% of patient with SEA were treated after transfer from another hospital. After adjusting for covariates, those who presented after transfer had higher odds of death during hospitalization (OR: 1.51, 95% CI 1.27-1.78, p<.001). Transferred patients were significantly more likely to live in rural communities (11.4 % vs. 5.3 % for nontransferred patients). CONCLUSIONS: Interhospital transfer, which occurred more frequently in patients from rural hospitals, was associated with death even after controlling for disease severity. Addressing healthcare delivery disparities across the US, including across the rural-urban spectrum, will require better understanding of the observed increased mortality of interhospital transfer as a preventable source of in-hospital mortality for SEA.