The economic costs to United States hospitals of invasive fungal infections in transplant patients

Background: Patients with a solid organ transplant (SOTs) and hematopoietic stem cell or bone marrow transplants (HSC/BMTs) are at risk of contracting invasive fungal infections (IFIs). Data on the economic burden of IFIs in the United States are sparse. Methods: We conducted a retrospective matched cohort study using the 2004-2005 Healthcare Cost and Utilization Project Nationwide Inpatient Sample. The IFI cohort included patients with ICD-9-CM codes indicating a transplant procedure and an IFI. Matched controls (transplant recipients without an IFI) were chosen based on age (10 year categories), sex, region, hospital type, year, and transplant type. Mortality, length of stay, and costs were reported overall, by transplant type, and by type of mycosis. Results: Nine thousand eight hundred ninety-six patients underwent SOT, and 4661 underwent HSC/BMT. Of these, 80 (0.8%) SOT and 111 (2.4%) HSC/BMT patients had an IFI. Mean age was 41.8 years (SOT) and 37.8 years (HSC/BMT). Aspergillosis was the most common infection. Patients with an IFI had a 5-fold increase in mortality, an additional 19.2 hospital days, and $55,400 in excess costs compared with patients without an IFI. Excess mortality, length of stay, and costs varied by type of transplant and mycosis. Conclusion: The clinical and economic burden of IFIs in transplant recipients may be high.