Outcomes of Ventilated Patients With Sepsis Who Undergo Interhospital Transfer: A Nationwide Linked Analysis

Abstract

Objectives The outcomes of critically ill patients who undergo inter-hospital transfer (IHT) are not well understood. Physicians assume that patients who undergo IHT will receive more advanced care that may translate into decreased morbidity or mortality relative to a similar patient who is not transferred. However, there is little empirical evidence to support this assumption. We examined country-level U.S. data from the Nationwide Readmissions Database to examine whether, in mechanically ventilated (MV) patients with sepsis, IHT is associated with a mortality benefit.

Design Retrospective data analysis using complex survey design regression methods with propensity score matching.

Setting The Nationwide Readmissions Database contains information about hospital admissions from 22 States, accounting for roughly half of U.S. hospitalizations; the database contains linkage numbers so that admissions and transfers for the same patient can be linked across one year of follow-up.

Patients From the 2013 NRD Sample, 14,325,172 hospital admissions were analyzed. There were 61,493 patients with sepsis and on MV. Of these, 1630 (2.7%) patients were transferred during their hospitalization. A propensity-matched cohort of 1630 patients who did not undergo IHT was identified.

Interventions None.

Measurements and Main Results The exposure of interest was inter-hospital transfer to an acute care facility. The primary outcome was hospital mortality; the secondary outcome was hospital length of stay (LOS). The propensity score included age, gender, insurance coverage, do not resuscitate (DNR) status, use of renal replacement therapy, presence of shock and Elixhauser co-morbidities index. After propensity matching, IHT was not associated with a difference in in-hospital mortality (12.3% IHT vs 12.7% non-IHT, p=0.74). However, IHT was associated with a longer total hospital LOS (12.8 days IQR 7.7–21.6 for IHT vs 9.1 days IQR 5.1–17.0 for non-IHT, p<0.01).

Conclusions Patients with sepsis requiring MV who underwent IHT did not have improved outcomes compared to a cohort with matched characteristics who were not transferred. The study raises questions about the risk-benefit profile of IHT as an intervention.