Association between interhospital transfer status and outcomes following nontraumatic subdural hemorrhage.

Background: Patients with nontraumatic subdural hemorrhage often require immediate surgical intervention that may not be available at community hospitals and are therefore transferred to tertiary care centers. This study aims to evaluate the effects of interhospital transfer (IHT) on postoperative complications and outcomes following ntSDH.

Methods: The National Surgical Quality Improvement Program (NSQIP) database was queried for patients treated for ntSDH from January 2014 to January 2020. Baseline demographics, clinical characteristics, postoperative complications, and postoperative outcomes compared based on IHT status. Univariate and multivariate logistic regression analyses were performed. Effect sizes in the final model were presented as odds ratio (OR) with associated 95% confidence interval (CI).

Results: Of the 715 included patients, 295 (41.3 %) were in the IHT cohort. Non-IHT patients demonstrated significantly increased progressive renal insufficiency (1.90 % vs 0.00 %, p = 0.043) and 30-day readmission rates (11.9 % vs 6.10 %, p = 0.003) when compared with IHT patients. IHT was associated with significantly increased odds of postoperative sepsis (OR = 1.37, p = 0.009), 30-day mortality (OR = 1.20, p = 0.011), and non-home disposition (OR = 1.14, p = 0.003).

Conclusions: Despite similar baseline characteristics, patients transferred for ntSDH treatment are associated with worse postoperative outcomes. Future studies should be conducted to identifying specific factors associated with IHT and poor outcomes.