Principal-agent theory-based cost and reimbursement structures of isavuconazole treatment in German hospitals.

Background: Isavuconazole (ISA) is a frequently used antifungal agent for the treatment of invasive fungal diseases (IFDs). However, hospital reimbursement data for ISA is limited.

Objectives: The primary objective of this study was to analyse the different perspectives of relevant stakeholders and the (dis)incentives for the administration of ISA in Germany. To that aim, the health economic effects of using ISA from a hospital management perspective were analysed.

Patients/methods: Based on principal-agent theory (PAT), the perspectives of (a) the patient (principal) as well as (b) physicians, (c) pharmacists and iv. hospital managers (all agents) were analysed. For the evaluation of the cost-containment and reimbursement strategies of ISA, the German diagnosis-related group (G-DRG) system was used.

Results: Hospitals individually negotiating additional payments for innovative treatment procedures (zusatzentgelte [ZE]) within the G-DRG system is a key element of hospital management for the reduction of total healthcare expenditure. Our analysis demonstrated the beneficial role of ISA in healthcare resource utilisation, primarily due to a shortened overall length of hospital stay. Depending on underlying disease, coded G-DRG and ISA formulation, large differences in total reimbursement and the amount of ZE was shown. The PAT demonstrated disincentives for hospital managers to use innovative drugs.

Conclusions: Based on the PAT, beneficial, detrimental and indifferent perspectives of different stakeholders regarding the usage of ISA were shown. A reduction of bureaucratic hurdles is needed in Germany for the extension of effective and innovative antifungal treatment strategies with ISA.