Interhospital Transfer for Patients with COVID-19 Admitted to an Urban Academic Medical Center in Chicago, IL

RATIONALE: Many hospitals were unable to accommodate the rapid surge of critically ill patients with COVID-19 requiring intensive care unit (ICU) admission in the spring of 2020. As a result, some patients were transferred to tertiary referral centers with increased surge capacity and an ability to provide a higher level of care for patients in respiratory failure requiring mechanical ventilation. In general, interhospital transfers have higher disease severity, longer length of stay, and higher mortality. Our study investigated whether patients with COVID-19 who were transferred to a tertiary referral center had higher severity of illness and poorer health outcomes compared to patients who were directly admitted. METHODS: This was a single center, retrospective cohort study of adult patients with COVID-19 who received mechanical ventilation. Demographic and clinical variables were extracted from the electronic medical record for patients admitted and discharged between March 17, 2020 and September 30, 2020. Patients were classified as either directly admitted or admitted via interhospital transfer. Inverse probability weighted regression models were constructed to test the association between transfer status and outcomes, including in-hospital death versus survival to hospital discharge, and number of days from intubation to discharge, adjusting for patient demographic characteristics and severity of illness. RESULTS: Of 1,785 patients admitted to Rush University Medical Center with COIVD-19, 174 (10%) were transferred from another hospital and 1,611 were directly admitted through the emergency department. A total of 119 transfer patients and 183 direct admits required mechanical ventilation. Transfer patients differed from direct admits in being more likely to have English as a preferred language (71% vs 56%,), younger age (median 57 vs 60 years), higher BMI (median, 34 vs 31), and more likely to have received ECMO (12% vs 3%), p<0.01 for each. Overall,150 (42%) transferred patients and 78 (43%) directly admitted patients died prior to discharge, and there was no significant difference in in-hospital mortality after adjusting for patient sociodemographic factors and presentation severity. Additionally, there were no significant difference found between days from intubation to discharge between the two groups. CONCLUSION: Although transferred patients may have been sicker on arrival when compared to directly admitted patients, there were no differences in in-hospital mortality or length of stay in this study. These data suggest that interhospital transfer of critically ill patients with COVID-19 can be done safely and effectively.