Utility Values Associated with Atypical Hemolytic Uremic Syndrome-Related Attributes: A Discrete Choice Experiment in Five Countries

Abstract

Background: Atypical hemolytic uremic syndrome is a rare disease caused by complement dysregulation that can lead to progressive kidney damage or death if untreated. Owing to its rarity, the impact of atypical hemolytic uremic syndrome and available therapies (eculizumab and ravulizumab) on patients' health-related quality of life is difficult to describe, but such data are required for an economic evaluation.

Objective: The objective of this study was to estimate utility values for atypical hemolytic uremic syndrome-related attributes in five countries for an economic evaluation.

Methods: Using discrete choice experiment surveys, key atypical hemolytic uremic syndrome-related attributes (life expectancy, administration frequency, risk of meningitis, need for hospitalization, and risk of kidney impairment) were evaluated in adult general population samples from Australia, Canada, the Netherlands, Sweden, and the UK. Survey choice sets were constructed using a published orthogonal array. A mixed-effects logit model estimated preference strength for each attribute. Utilities were estimated using marginal substitution rates between overall survival and other attributes, weighted against average life expectancy.

Results: Across all countries (N = 2382), utility weights revealed a consistent pattern: participants were averse to the risk of kidney impairment (disutility/utility weight range: -0.185 to -0.158), risk of meningitis (-0.041 to -0.032), and the need for hospitalization (-0.063 to -0.048), but preferred 8-weekly vs 2-weekly infusions over 1 h (0.013-0.039).

Conclusions: Although all attributes played a role in determining treatment preferences, the largest drivers were life expectancy and risk of kidney impairment. Participants favored 8-weekly dosing (corresponding to ravulizumab administration frequency) vs 2-weekly dosing. The discrete choice experiment was designed such that estimated (dis)utility weights can be used in future cost-effectiveness models in atypical hemolytic uremic syndrome.