Health-care utilization and outcomes of patients at high risk of invasive fungal infection

Rao Fu,1 Jake Gundrum,1 Anita H Sung2 1Premier Applied Sciences, Premier Inc., Charlotte, NC, USA; 2Merck & Co. Inc., Kenilworth, NJ, USA Purpose: The objectives of this study were to present trends in posaconazole use over time and describe selected outcomes among patients at high risk of invasive fungal infections (IFIs) by use and type of antifungal medicine. Methods: A retrospective observational study using data from the Premier Healthcare Database between January 2007 and March 2016 was conducted. Inpatient use of posaconazole by formulation and year is described. Separately, four cohorts of patients at high risk of IFI – those with acute myeloid leukemia (AML), myelodysplastic syndrome (MDS), hematopoietic stem-cell transplantation (HSCT), and graft-vs-host disease (GVHD) – but without a diagnosis code for IFI during the index encounter were identified as potential candidates for antifungal prophylaxis. Use of antifungal medication(s) in these patients was categorized. Index length of stay (LOS), index hospital costs, and subsequent inpatient and outpatient encounters with IFI at 30, 60, and 90 days post-index encounter are presented by antifungal group for each cohort. The percentage of patients with inpatient and outpatient encounters with IFI at 90 days post-index encounter was determined for each cohort by year. Results: Use of posaconazole oral suspension increased through 2012, then declined as the tablet formulation became available in 2013. A total of 19,872 AML patients, 12,125 MDS patients, 14,220 HSCT patients, and 5,431 GVHD patients were considered potential candidates for antifungal prophylaxis; however, a large proportion of patients within each cohort (33%–94%) did not receive any antifungal drug during the index hospitalization. Index LOS, hospital costs, and subsequent encounters for IFI varied among cohorts and by antifungal group. Within each cohort, subsequent encounters for IFI at 90 days post-index encounter fluctuated but remained rare across different years. Conclusion: Over time and as new posaconazole formulations became available, the frequency of use of each formulation changed. In addition, this study suggested a low rate of potential antifungal prophylaxis in high-risk patients. This is one of the first reports attempting to describe antifungal prophylaxis in a contemporary, large, all-payer, geographically representative hospital database. Keywords: prophylaxis, acute myeloid leukemia, myelodysplastic syndromes, hematopoietic stem-cell transplantation, graft-vs-host disease, health-care outcome