In-Hospital Morbidity and Mortality Among Acute Myeloid Leukemia Patients Admitted for Hematopoeitic Stem Cell Transplants between 2002-2014
Authors: Abbasi Saqib , Diab Osama , Mohyuddin Ghulam Rehman , Singh Anurag K. 
Published: November 2019

Introduction:
Acute myeloid leukemia (AML) is a disease with poor overall prognosis, about 4.3 per 100,000 men and women per year are diagnosed with AML with a deaths rate of 2.8 per 100,000. The incidence of AML increases with age which leads to an older population with multiple comorbidities and inferior prognosis. Hematopoietic stem cell transplant (HCT) remains the standard of care in most intermediate and high-risk AML patients. However, HCT puts these patients at risk of severe cytopenia, opportunistic infections, acute graft versus host disease and financial stress, especially in the early phases of transplant. The purpose of this study is to identify the annual trends in in-hospital mortality and morbidity associated with patients with AML admitted for HCT and impact of comorbid conditions on the likelihood of death during admission.
Method
Data was collected from the National Inpatient Sample from the years of 2002 to 2014. Admissions for HCT for acute myeloid leukemia patients were identified using a procedural clinical classification software code for bone marrow transplants in combination with ICD 9 codes for acute myeloid leukemia. Annual trends in mortality, hospital length of stay, and costs of admission were assessed with a linear regression analysis. Univariate logistic regression analysis was used to test for associations between chronic medical conditions and mortality among these patients. Co-morbid conditions were identified using the Agency for Healthcare Research and Quality comorbidity measures for underlying chronic conditions in patients in 2013 to 2014.
Results:
Between and including the years of 2002 to 2014, a total weighted estimate of transplants for acute myeloid leukemias in the United States totaled 31,811 (N=6,102). Annual transplants increased from 1,761 in 2002 to 3,030 in 2014. In-hospital mortality decreased from 8.4% in 2002 to 4.8% in 2014 (p=0.02). The mean length of stay remained unchanged from 32.8 days in 2002 to 32.7 days in 2014. Costs of admission increased from $226,280 to $474,106. In-hospital mortality in the years 2013 and 2014 were most strongly associated with comorbid conditions of congestive heart failure (Odds ratio (OR)=5.93), weight loss (OR=4.32), coagulopathy (OR=3.84), liver cirrhosis (OR=3.41). Any two of these conditions increased the OR to 8.34.
Conclusions:
HCTs have traditionally been associated with high upfront including in-hospital mortality. Our data demonstrates that in the last two decades mortality has been reduced by almost 50% while the length of hospital stay has not changed. This could be related to improvements in supportive care and better selection of conditioning regimens for the patients. It also shows that the costs of hospitalization has doubled. Congestive heart failure, weight loss, underlying coagulopathy and liver cirrhosis are most strongly associated with worse outcomes with any combination of these further potentiating risk of death. Careful selection of patients with special attention to the pre-existing comorbidities is the key to improving early outcomes in HCT. Consideration should also be given to expanding infrastructure to perform outpatient transplants to bend the cost curve.

Disclosures
No relevant conflicts of interest to declare.