OBJECTIVES: Primary hyperoxaluria type 1 (PH1) is a rare genetic disorder characterized by hepatic overproduction of oxalate. Excretion of excess oxalate by the kidneys leads to recurrent kidney stones, nephrocalcinosis, progressive kidney disease, and multiorgan damage from systemic oxalosis. Patients progressing to or presenting with kidney failure require invasive approaches such as dialysis and liver and/or kidney transplantation. There is currently little evidence about the impact of PH1 on health-related quality of life (HRQoL). This study aimed to understand the burden of PH1 on patients by eliciting utilities to support future economic evaluations.

METHODS: A targeted literature review and interviews with one pediatric and one adult PH1 clinical expert (n=2) informed the development of health state vignettes describing the impact of PH1. PH1 states were defined based on chronic kidney disease (CKD) stages in adults and children. A post-combined liver and kidney transplant (CLKT) health state was also developed. The health states were valued by members of the UK general public using the EQ-5D-5L and time trade-off (TTO) methods.

RESULTS: One hundred participants valued the health states; (50% male, mean age 41 years). Scores were lowest for CKD5 child (EQ-5D-5L=-0.05, TTO=0.33) and adult states (EQ-5D-5L=0.02, TTO=0.39), with large decrements observed between the early CKD stages and the dialysis states (CKD4 and CKD5). CLKT scores were comparable to those of the early CKD stages (1-3b) in both adult and child states.

CONCLUSIONS: This study yielded a novel set of utility values in PH1. Mean EQ-5D-5L and TTO and ratings followed a similar pattern, although EQ-5D-5L values were consistently lower. The results demonstrate the considerable impact on HRQoL associated with PH1, with this impact being greatest as the disease advances and dialysis is required. These data can be used in future economic evaluations of treatments to inform decision-making.