Clinical and Economic Burden of Invasive Mucormycosis: A Multicenter Cost-of-Illness Analysis of Patients Treated in German Tertiary Care Hospitals between 2005 – 2016

Background: Incidence rates of invasive mucormycosis (IM) markedly increased during the past decade. However, data concerning the clinical and economic burden of IM are scarce.

Methods: We performed a retrospective cost-of-illness analysis of cases with IM extracted from FungiScope – Global Registry for Emerging Fungal Infections. To analyze direct inpatient treatment costs and length of stay, a further registry was set up on www.ClinicalSurveys.net and physicians were invited to provide additional information concerning the most important cost drivers in treatment of IM. This health economic evaluation was carried out based on national guidelines and results were compared to patients with similar underlying diseases based on the German Diagnosis Related Groups (G-DRG) system who did not develop an IM.

Results: To date, 40 patients with probable/proven IM from three German tertiary care centers were included into analysis. Most patients were male (n= 27, 67.5%) and median age was 58 years (range: 11 – 88 years). The most common risk factors were hematological disorders (n= 35, 87.5%), chemotherapy (n= 27, 67.5%), and allogeneic stem cell transplantation (n= 14, 35%). Lungs were identified as site of infection in 32 patients (80%) and 24 patients (60%) received antifungal prophylaxis prior to diagnosis of IM. Mean overall length of stay of patients with IM were 57.0 days (95% CI: 47.4 – 66.7 days). Analysis of cost factors identified the primary cost drivers as antifungal treatment due to IM €20,836 (95% CI: €11,314 - €30,358) and treatment on specialized care units (intermediate care unit, bone marrow transplant unit, intensive care unit) €18,209 (95% CI: €10,453 - €25,965), resulting in mean overall direct treatment costs of €52,820 (95% CI: €36,129 - €69,511). Compared to patients coded with the same G-DRG but without IM, patients with IM were treated in hospital for 26.3 (95% CI: 18.3 – 34.3 days; P< 0.001) additional days, resulting in mean additional costs of €33,033 (95% CI: €19,000 - €47,066; P< 0.001). Eighteen patients (45%) died during hospitalization.

Conclusion: Our comprehensive cost-of-illness analysis demonstrates the clinical and economic burden of IM. Most important cost drivers were antifungal drug acquisition and treatment on specialized care units. Innovative treatment strategies are needed to improve patient outcome and reduce treatment costs.