Background: Invasive fungal infections (IFIs) in immunocompromised patients (e.g. those receiving chemotherapy or hematopoietic stem cell transplantation) are associated with high mortality. To mitigate this risk, patients in Egyptian clinical practice generally receive empirical antifungal therapy if they present with unresponsive neutropenic fever (febrile for ≥72 hours on broad-spectrum antibiotic therapy) without confirmed IFI. An alternative approach is to treat patients with a diagnostic-driven (DD) strategy using diagnostic tests (beta-galactomannan [GM] assessment and aspergillus polymerase chain reaction [PCR] tests) to identify patients with IFIs prior to initiating antifungal treatment upon a positive diagnostic evaluation. The present study used a cost-effectiveness model to compare the economic costs and clinical outcomes for these strategies in Egypt.
Materials/methods: A decision analytic model was used to estimate costs and clinical outcomes associated with the standard empirical strategy (in which all patients with unresponsive neutropenic fevers received conventional amphotericin B [C-AMB], liposomal amphotericin B [L-AMB], caspofungin or voriconazole), compared with a DD strategy (in which patients received C-AMB, L-AMB or voriconazole based on PCR/GM confirmation of invasive aspergillosis) in immunocompromised patients with persistent fever. A hypothetical cohort of 1000 adult patients were assumed to have been neutropenic for more than 10 days. Survival rates for each strategy were calculated based on the proportion of patients with correctly identified and appropriately treated IFIs (assumed to improve overall survival by a hazard ratio of 0.589 based on published literature). The diagnostic test sensitivity was 67.7% based on literature review. Resource uses and costs were obtained from expert opinion and local tariffs. Costs were reported in 2015 US dollars ($).
Results: Total costs associated with the DD strategy were lower ($4,076) than with the empirical strategy ($4,717), with antifungal therapy treatment costs lower with the DD strategy ($725) than with the empirical strategy ($865) despite the higher use of generic C-AMB in the latter. Total other medical costs were lower with the DD strategy ($3,343; PCR/GM costs were $1,138) than with the empirical strategy ($3,841; PCR/GM costs were $165). The number of patients estimated to receive antifungal therapy in each cohort was 74 with the DD strategy and 125 with the empirical strategy; survival was similar (90.2% vs 89.6%, respectively). The DD strategy was dominant with lower total costs and better outcomes than the empirical strategy.
Conclusions: Total costs and antifungal treatment costs were lower with the DD strategy than with the empirical strategy, largely due to a more targeted treatment population with the DD strategy and additional medical costs associated with the empirical strategy. This cost-effectiveness model suggests that the DD approach may be a cost-saving management strategy in Egypt for immunocompromised patients with persistent fever.
Full conference title:
- ECCMID 26th (2016)