PSY7 A CONCEPTUAL FRAMEWORK FOR ECONOMIC EVALUATION OF BETA-THALASSEMIA

Abstract

To establish a conceptual framework to aid in the economic evaluation of the treatment of beta-thalassemia (BT) to assess cost-effectiveness, long-term effects, and resource use. An economic conceptual framework was developed from a US payer perspective using literature and clinical rationale. Efficacy and safety outcomes, health states, technical assumptions, economic endpoints, and costs were considered. Key value drivers were identified to help optimize future economic models. Different sets of assumptions were considered and tested using a Markov model. The model framework and clinical rationale were validated by expert hematologists. A lifetime horizon was modeled because patients with BT often require lifelong red blood cell transfusions (RBCTs). In addition to disease pathology, RBCTs lead to iron loading and contribute to significant morbidity (e.g. increased long-term complications, complication costs, reduced quality of life) and early mortality. A lifetime horizon further permitted the use of age-related increases for complication rates and captured the long-term outcomes of key therapies (curative or otherwise). Six health states were modeled to capture the patient lifetime journey: transfusion-independence, low transfusion burden, medium transfusion burden, high transfusion burden, treatment discontinuation, and mortality. These health states enabled the inclusion of response status defined in terms of transfusion burden and treatment discontinuation. The cost of iron chelation therapy was a key driver across health states, increasing costs with greater transfusion burden. Drug costs, routine care, complication(s), adverse events, mortality, and indirect costs were also key drivers. This conceptual model framework permitted the reporting of results in incremental costs per QALY, LY, and responder. This conceptual framework can be used to perform future economic evaluations of the treatment of BT, to capture long-term effects, complications, and mortality, and to provide researchers and policymakers with the appropriate tools for informed decision-making.