Trends of Azole Antifungal Prescription in the United States: Medicare Part D Provider Utilization and Payment Data Analysis

Background Invasive fungal infections carry a substantial risk of mortality and morbidity. Azole antifungals are used in the treatment of such infections; however, their extensive use can lead to the emergence of antifungal resistance and increased costs to patients and healthcare systems. The aim of this study is to evaluate trends in these antifungals use and costs. Methods The secular and regional trends of outpatient azole antifungals were analyzed using Medicare Part D Prescriber Public Use Files for the years 2013-2020. The total days supply (TDS), total drug cost (TDC) per 100 000 enrollees, and cost per day (CPD) were evaluated. Results The azole antifungal TDS for Medicare Part D enrollees increased by 12% between 2013 and 2020, and increases were noted for each azole. Southern US regions had the highest TDS, with Arizona having the highest TDS among US states in 2020. Cost analysis showed that TDC of all azoles has increased by 93% over the years, going up from $123 316 in 2013 to $238 336 per 100 000 enrollees in 2020. However, CPD showed an increase only for fluconazole and isavuconazole, with CPD of $1.62 per day and $188.30 per day, respectively. Conclusions Combined azole antifungal prescriptions TDS increased among Medicare Part D enrollees. The trend in CPD was mixed, whereas overall costs consistently increased over the same period. Such findings provide an insight into the impact of azole antifungal prescriptions, and increasing use could foreshadow more antifungal resistance. Continued studies to evaluate different prescribers' trends are warranted.