Societal costs and quality of life associated with arginase 1 deficiency in a European setting - a multinational, cross-sectional survey.

Background and aims: Arginase 1 deficiency (ARG1-D) is a ultrarare disease with manifestations that cause mobility and cognitive impairment that progress over time and may lead to early mortality. Diseases such as ARG1-D have a major impact also outside of the health care sector and the aim of this study was to estimate the current burden of disease associated with ARG1-D from a societal perspective.

Methods: The study was performed as a web-based survey of patients with ARG1-D and their caregivers in four European countries (France, Portugal, Spain, United Kingdom). The survey was distributed at participating clinics and included questions on e.g. symptoms (including the Gross Motor Function Classification System, GMFCS, and cognitive impairment), health care use, medication, ability to work, caregiving, and impact on health-related quality-of-life (HRQoL) using the EQ-5D-5L.

Results: The estimated total mean societal cost per patient and year was £63,775 (SD: £49,944). The cost varied significantly with both mobility impairment (from £49,809 for GMFCS level 1 to £103,639 for GMFCS levels 3-5) and cognitive impairment (from £43,860 for mild level to £99,162 for severe level). The mean utility score on the EQ-5D-5L for patients was 0.498 (SD: 0.352). The utility score also varied significantly with both mobility impairment (from 0.783 for GMFCS level 1 to 0.153 for GMFCS level 3-5) and cognitive impairment (from 0.738 for mild level to 0.364 for severe level).

Conclusions: Similar to other studies of rare diseases, the study is based on a limited number of observations. However, the sample appear to be reasonably representative when comparing to previous studies of ARG1-D. This study shows that ARG1-D is associated with a high societal cost and significant impact on HRQoL. Earlier diagnosis and better treatment options that can postpone or withhold progression may therefore have a potential for improved HRQoL and savings for the patient, caregiver, and society.