Critical Care Utilization and Outcomes of Interhospital Medical Transfers at Lower Risk of Death

Purpose: To evaluate utilization and mortality outcomes of interhospital transferred critically-ill medical patients with lower predicted risk of hospital mortality. Materials & Methods: Multisite retrospective cohort analysis of patients with Acute Physiology and Chronic Health Evaluation (APACHE) IV-a predicted mortality of ≤20% from 335 ICUs in 208 hospitals in the Philips eICU database between 2014-2015. Differences in length-of-stay (LOS) and mortality between transferred and local patients were evaluated using negative binomial logistic regression and logistic regression, respectively. Stratified analyses were conducted for subgroups of predicted mortality: 0%-5%, 6%-10%, 11%-15%, and 16%-20%. Results: Transfers had a higher risk of longer ICU and hospital LOS across all risk strata (IRR 1.12; 95% CI 1.09-1.16, P < 0.001 and IRR 1.11; 95% CI 1.07-1.14, P < 0.001 respectively). Mortality was higher among transfers, largely driven by the 6%-10% mortality risk strata (OR 1.30; 95% CI 1.09-1.54, P = 0.003). Conclusions: Interhospital transfer of critically-ill medical patients with lower illness severity is associated with higher ICU and hospital utilization and increased mortality. Better understanding of factors driving patient selection for and characteristics of interhospital transfer for this population will have an impact on ICU resource utilization, care efficiency, and hospital quality.