OBJECTIVES: TDT is a rare genetic disease with impaired production of healthy red blood cells due to insufficient adult hemoglobin (HbA) production. The resulting ineffective erythropoiesis, and iron overload from chronic transfusions, makes this a complex disease. Cost-utility analyses in TDT to-date use health-state utility values that have not been compared to disease-specific quality of life (QoL) measures. This study aimed to contextualize TDT utility-value estimates with disease-relevant data.

METHODS: Eligible participants were US patients >12 years old (yo) with TDT. Participants completed TranQoL, a TDT-specific measure of QoL, and reported the timing of most recent blood transfusion. Participants 12–15 yo completed the EQ-5D-Y and participants >16 yo completed the EQ-5D-3L. As a US value set for EQ-5D does not exist, scores were derived using the value set for Spain.

RESULTS: 23 participants >16 yo (mean age: 36.9 yo) and 9 participants 12–15 yo (mean age: 13.0 yo) completed interviews. Mean (SD) TranQoL score was 67.12 (17.53) among participants >16 yo, and 77.58 (9.07) among participants 12–15 yo. Mean (SD) EQ-5D-3L score was 0.86 (0.15), with 42.9% of participants at the ceiling (i.e., 1.0). Mean (SD) EQ-5D-Y score was 0.93 (0.09), with 55.6% at the ceiling. The EQ-5D-3L was correlated with the TranQoL (r=0.71; p<0.001), but with notable variation (e.g., TranQoL scores ranged from 60.3–95.8 for those with EQ-5D=1). Neither EQ-5D version correlated significantly with days since last RBC transfusion (-3L: r=-0.097 (p=0.676); -Y: r=-0.345 (p=0.362)), a TDT burden indicator.

CONCLUSIONS: TranQoL scores were consistent with the literature. The substantial ceiling effect suggests EQ-5D may not be sensitive to QoL impact in TDT. Low correlation of EQ-5D with days since transfusion raises questions about sensitivity to clinical burden. Additional research on EQ-5D and TranQoL correlation is warranted.