Evaluation of Early Discharge after Intensive Induction Chemotherapy in Adults with Acute Myeloid Leukemia
Authors: Al-Bahou Amanda , Richter Katherine A. , Snyder Matthew , Rockwell Sarah J. , Yun Seongseok , Kubal Timothy E. 
Published: November 2021

Abstract
Background: Acute myeloid leukemia (AML) patients who require intensive induction chemotherapy are traditionally hospitalized for the duration of neutropenia to monitor for treatment-related toxicities. On average, AML patients are hospitalized for 33.7 days during first induction treatment (Sacks et al Clin Ther 2018). Prolonged hospitalizations are associated with substantial costs, increased risk for nosocomial infections, and significant declines in physical function and quality of life. Several studies have evaluated the impact of early discharge prior to neutrophil recovery, however current evidence has not clearly defined the ideal patient characteristics or described the optimal time post-induction to safely discharge patients. At our institution, we established a "STREAMLINE (Safe TRansition with Early-discharge in Acute Myeloid Leukemia INtensivE-induction) Protocol" to evaluate patients for early discharge following induction chemotherapy.
Objective: To determine the optimal time after induction chemotherapy to safely discharge AML patients.
Methods: Retrospective, single-institution review of adult AML patients who received intensive induction chemotherapy from January 1, 2017 to December 31, 2019. The STREAMLINE criteria for early discharge (Table 1) was retrospectively applied at discharge timepoint-1 (DT1) and discharge timepoint-2 (DT2). DT1 was defined as within 24 hours following completion of induction therapy and DT2 was defined as within 24 hours after performance of first bone marrow biopsy after induction therapy. Each patient served as his/her own control to compare actual length of hospitalization to the length of hospitalization if the patient had been discharged at DT1 and/or DT2. The primary outcome was number of hospital days saved if discharged at DT1 compared to DT2. Secondary outcomes included proportion of patients who met STREAMLINE criteria, incidence and time to first complication that would require hospital readmission for patients who met criteria, overall days of hospitalization, and overall survival at 30 and 60 days.
Results: A total of 284 patients met inclusion criteria and were assessed for early discharge. Eighty-nine patients (31.3%) met the STREAMLINE criteria for early discharge with 51 (57.4%) at DT1, 19 (21.3%) at DT2, and 19 (21.3%) at DT1 and DT2. Baseline demographics of the study population are described in Table 2. Of the 195 patients (68.7%) ineligible for early discharge, 118 (60.5%) were ineligible due to an active medical issue or laboratory parameter not met, 60 (30.8%) due to age, 9 (4.6%) due to poor performance status, and 8 (4.1%) due to history or evidence of heart failure. The most common laboratory or active medical issues that led to ineligibility were the need for intravenous anti-infectives (34.9%), fever within 48 hours of discharge timepoint (29.3%), and transfusion dependence (24.5%). Study outcomes are summarized in Table 3. In the 70 patients who met STREAMLINE criteria at DT1, 60 (94.3%) experienced an event that would require hospital readmission (Figure 1). The most common were neutropenic fever (42.9%), proven infection (31.4%), and re-induction therapy (7.1%). The median time to readmission event was 6 days [interquartile range (IQR) 3-10]. Based on early discharge at DT1, median length of hospitalization was 26 days (IQR 19-33) with a median 6 days saved (IQR 2-9.8). In the 38 patients who met STREAMLINE criteria at DT2, 26 (68.4%) experienced an event that would require hospital readmission (Figure 1). The most frequent were neutropenic fever (28.9%), re-induction therapy (18.4%), and proven infection (13.2%). The median time to readmission event was 3 days (IQR 2-5). Based on early discharge at DT2, the median length of hospitalization was 25.5 days (IQR 22-40) with a median 3 days saved (IQR 1-5). Overall, early discharge at DT1 was predicted to save a total of 468 days compared to a total of 165 days at DT2. In all patients who met STREAMLINE criteria (n=89), overall survival at 30- and 60-days post-induction therapy was 100%.
Conclusions: Early discharge at DT1 was predicted to save a greater number of hospital days compared to DT2, however DT1 was associated with higher readmission events. These findings suggest that early discharge is safe and feasible in AML patients who receive intensive induction therapy.
Figure 1 Figure 1.

Disclosures
No relevant conflicts of interest to declare.