The Impact of Timing on Clinical and Economic Outcomes During Inter-ICU Transfer of Acute Respiratory Failure Patients: Time and Tide Wait for No One

Abstract

IMPORTANCE AND OBJECTIVE: Approximately one in 30 patients with acute respiratory failure (ARF) undergoes an inter-ICU transfer. Our objectives are to describe inter-ICU transfer patterns and evaluate the impact of timing of transfer on patient-centered outcomes. DESIGN: Retrospective, quasi-experimental study. SETTING: We used the Healthcare Cost and Utilization Project State Inpatient Databases in five states (Florida, Maryland, Mississippi, New York, and Washington) during 2015–2017. PARTICIPANTS: We selected patients with International Classification of Diseases, 9th and 10th Revision codes of respiratory failure and mechanical ventilation who underwent an inter-ICU transfer (n = 6,718), grouping as early (≤ 2 d) and later transfers (3+ d). To control for potential selection bias, we propensity score matched patients (1:1) to model propensity for early transfer using a priori defined patient demographic, clinical, and hospital variables. MAIN OUTCOMES: Inhospital mortality, hospital length of stay (HLOS), and cumulative charges related to inter-ICU transfer. RESULTS: Six-thousand seven-hundred eighteen patients with ARF underwent inter-ICU transfer, 68% of whom (n = 4,552) were transferred early (≤ 2 d). Propensity score matching yielded 3,774 well-matched patients for this study. Unadjusted outcomes were all superior in the early versus later transfer cohort: inhospital mortality (24.4% vs 36.1%; p < 0.0001), length of stay (8 vs 22 d; p < 0.0001), and cumulative charges ($118,686 vs $308,977; p < 0.0001). Through doubly robust multivariable modeling with random effects at the state level, we found patients who were transferred early had a 55.8% reduction in risk of inhospital mortality than those whose transfer was later (relative risk, 0.442; 95% CI, 0.403–0.497). Additionally, the early transfer cohort had lower HLOS (20.7 fewer days [13.0 vs 33.7; p < 0.0001]), and lower cumulative charges ($66,201 less [$192,182 vs $258,383; p < 0.0001]). CONCLUSIONS AND RELEVANCE: Our study is the first to use a large, multistate sample to evaluate the practice of inter-ICU transfers in ARF and also define early and later transfers. Our findings of favorable outcomes with early transfer are vital in designing future prospective studies evaluating evidence-based transfer procedures and policies.

Interhospital Transfer of Patients With Acute Respiratory Failure in the United States: A Scoping Review

“…The 16 articles included in this review were observational in nature, with 14 retrospective analysis that used either administrative databases (15)(16)(17)(18)(19)(20) or electronic health record data (21)(22)(23)(24)(25)(26)(27)(28). One study was prospective in nature and examined the reasons behind patient transfer (29), while another evaluated the efficacy of an intervention on transfer wait times and outcomes (30).…”

“…Some studies have used acute illness severity indicators like the Acute Physiology and Chronic Health Evaluation scoring system ( 22 ) and Sequential Organ Failure Assessment (SOFA) scores ( 23 ) to describe patient characteristics, which are both predictive scoring systems to assess the magnitude of a patient’s illness as well as prognosticate risk of mortality. However, a majority have used administrative data sources and report use of Charlson Comorbidity Index ( 16 , 17 ), total Elixhauser comorbidity score ( 15 , 18 , 19 , 25 ), or other models ( 21 ) that largely capture comorbidities and not acuity at time of disease presentation. Some have excluded severity of illness altogether ( 24 , 29 , 31 ), leading to the inability to accurately risk stratify patients either during their initial hospital course or events that occur after transfer.…”

“…One retrospective study using HCUP state inpatient database (2015–2017) from five states ( n = 6718) found that 65% of the transferred cohort were transferred within 2 days of initial ICU admission characterized as early transfers; these early transfers were found to have a lower relative risk of in patient mortality (0.442; 95% CI, 0.403–0.497; p < 0.0001) and shorter length of hospital stay (20.7 fewer days [13.0 vs. 33.7; p < 0.0001]) compared with a propensity matched cohort transferred later (> 3 d). However, this study was limited and did not have information on clinically derived illness severity scores, reason(s) for transfer, ICU capacity strain, and staffing models ( 17 ). A similar retrospective study of ARF transfers ( n = 1269) at a single academic center showcased a median length of stay (LOS) of 4 days (interquartile range [IQR], 2–8 d) at the initial hospital before transfer and found that a longer LOS at the initial hospital was independently associated with increased mortality (OR, 1.029; 95% CI, 1.008–1.050; p < 0.005) ( 22 ).…”

“…Furthermore, the evidence reviewed here is predominantly retrospective with a heterogeneous ARF patient population. While the majority of studies used diagnosis or procedural coding to specifically identify ARF patients who required mechanical ventilation (15–19, 21, 24, 31), other studies included patient cohorts with a broader range of respiratory support, from supplemental oxygen to ECMO with varying clinical characteristics provided (20, 22, 23, 26–29). Additionally, there was a paucity of studies specifically addressing the utilization of NIV and high-flow oxygen as modes of support for the transferred ARF population despite a large increase in prevalence of NIV in recent years (36).…”

“…Where: Destinations for Patients With ARF Who Undergo Interhospital Transfer. Two retrospective studies using administrative data and evaluating transfer patterns in multiple states report that transfers occur typically from smaller hospitals (bed number < 100) to larger hospitals (bed number > 300); larger hospitals in these studies were further characterized by including information on annual ARF volume, annual ICU volume, and availability of expertise with ECMO and transplants (16,17). Given the demonstrated safety of transport while on ECMO support, access to high-volume regional centers has increased due to expansion of their catchment area (27).…”