Comparing Outcomes Amongst Mechanically Ventilated Patients Who Are Transferred vs Retained in a Large Health System

<h3>Background</h3> Mechanically ventilated (MV) patients undergoing a transfer to a higher-resourced hospital have variable outcomes. We aimed to evaluate patient outcomes by transfer status and timing. <h3>Research Question</h3> What are the characteristics and outcomes of mechanically ventilated patients who are transferred from 1 ICU to another? Does timing of transfer affect these outcomes? <h3>Study Design and Methods</h3> In a retrospective observational study, we identified patients admitted on a ventilator to a Midwestern health system (7 local hospitals, 1 tertiary hospital) from March 2018 to December 2021. Exposures were transfer status (being transferred to a tertiary hospital or retained at a local hospital) and transfer timing (early transfers if transferred ≤ 2 days after admission or late transfers). Propensity score weighting was used to balance patient characteristics (age, sex, race/ethnicity, insurance, comorbidity, and primary diagnosis) and baseline clinical factors (admission Sequential Organ Failure Assessment score, COVID-19 test, days on mechanical ventilation, major surgery, and ICU use of dialysis, tracheostomy, and vasopressors). Associations with exposures were estimated through multinomial logistic regression for discharge destination or negative binomial regression for total length of stay (LOS). <h3>Results</h3> Of a total of 5,883 adult MV patients, 5,719 were retained and 164 were transfers (80 early transfers and 84 later transfers). Transfers were associated with longer LOS (33.4 days vs 10.2 days; incident rate ratio [IRR] = 3.11; 95% CI, 2.53-3.82; <i>P</i> < .001) and had an increased likelihood of discharge to other facilities (rehabilitation and nursing facilities) (OR = 2.62; 95% CI, 1.51-4.56; <i>P</i> < .01) than retained patients at the local hospitals. Additionally, early transfer was found to be associated with a shorter LOS than late transfers (19.6 days vs 47.7 days; IRR=0.41; 95% CI, 0.33-0.51; <i>P</i> < .01). <h3>Interpretation</h3> Our results show that MV patient transfers within our health system have lower likelihood of discharge to home and longer LOS when compared with MV patients retained at local hospitals. However, the time to transfer may be an important contributor to better outcomes.