Acute myeloid leukemia (AML) is the most common acute leukemia in adults, and treatment outcomes have improved only modestly in recent decades. Ankit Shah, MD, Drexel University College of Medicine, Philadelphia, PA, sought to analyze the differences in trends between teaching versus non-teaching medical institutions for admitted adult patients with active AML in terms of hospital cost, length of stay, in-hospital mortality, and complication rates. Shah presented the research team’s analysis findings at the 58th American Society of Hematology Annual Meeting and Exposition in San Diego, CA.  

Using the Nationwide Inpatient Sample (NIS), study authors collected ICD-9 codes between 1999 and 2013 for AML and acute monocytic leukemia and included more than 51,000 adult admissions with a primary diagnosis of active AML. Admission data such as length of stay (LOS), total charges, and mortality were collected, and total cost was adjusted for inflation. Researchers focused on ICD-9 codes that reflect the most common etiologies of in-hospital complications such as sepsis, pneumonia, venous thromboembolism (VTE), candidiasis, urinary tract infection (UTI), and acute respiratory failure.  

The complication rates were examined for a 15-year interval, compared between teaching and non-teaching hospitals.  

Researchers found that most of the admissions were at teaching hospitals. Several differences between the teaching and non-teaching hospitals emerged through analysis.  

  • LOS (days) was found to be longer in teaching hospitals (21.04 days). 
  • Total charges were also greater in teaching hospitals (more than $157,000 compared to more than $79,000). 
  • At 19.54%, after correcting for age, multivariate analysis yielded higher mortality in teaching than in non-teaching hospitals. 
  • Rates of bacteremia, neutropenic fever, sepsis, acute respiratory failure, and VTE were higher in teaching hospitals, but rates of UTI were lower in teaching facilities. 
  • Rates of pneumonia and candidiasis did not have a statistically significant difference when comparing the two settings.  

The study also showed that in-hospital mortality declined by more than one-third for all AML admissions. Rates of nearly all studied complications, excluding candidiasis, increased during the time period. Total charges also increased, from $66,678 in 1999 to $197,439 in 2013, which was more than the anticipated inflationary growth to $93,235 over the same time period. 

Shah and colleagues presented possible causes for some of these trends. Th increased cost of admissions for AML at teaching intuitions may be caused by increased resource requirements to care for this patient population, for example. And although in-hospital mortality improved greatly between 1999 and 2013, rates of studied complications increased. “Given the opposite trend in mortality, we believe this may be in part due to improved surveillance and reporting,” he said. Moreover, total charges were greater at teaching institutions, perhaps because of medical LOS, complication rates, medical complexity, and resource consumption. 

“Further research is required to determine what additional factors and practice differences are contributing to these discrepancies,” Shah said.