A Vignette Study to Derive Health-Related Quality-of-Life Weights for Individuals with Steroid Refractory Chronic Graft-versus-Host Disease Receiving Third-Line Therapy in the United Kingdom.

Abstract

Background: Chronic graft-versus-host disease (cGvHD) - a potentially debilitating complication of allogeneic hematopoietic stem cell transplantation - is a rare condition. Objectives: This vignette-based study aimed to generate utility values to inform an economic model via an online survey wherein cGvHD health state (HS) vignettes were valued by the general UK population using the EQ-5D-5L and the EQ-5D-visual analog scale (EQ-5D VAS). Methods: This non-interventional health-related quality of life (HRQoL) study was conducted in 3 stages across the UK: the development, validation, and valuation of HS vignettes to generate utility values for cGvHD. Four HS for cGvHD were defined based on an economic model partitioning different treatment level responses in patients with cGvHD receiving third-line (3L) therapy (HS1: complete response, HS2: partial response, HS3: lack of response, and HS4: recurrent cGvHD). Draft vignettes were developed for each HS based on 4 previously published GvHD vignettes. The contents of the draft vignettes were reviewed for all aspects of cGvHD symptoms and functional impact and validated through semistructured interviews with 5 clinical experts. The 4 finalized HS vignettes were valued by 300 participants from the UK general population using EQ-5D-5L and EQ-5D VAS. Results: Previously published vignettes were used to develop the vignettes for the current study that described GvHD in the context of blood cancer and other rare blood disorders (n = 2 each) and included symptoms, functioning, and quality of life for a patient in the HS. The highest and lowest mean EQ-5D-5L utility scores were observed for HS1 (mean [95% CI]: 0.577 [0.558-0.595]) and HS4 (0.061 [0.034-0.088]), respectively. The EQ-5D-VAS showed the highest and lowest mean utility scores for HS1 (46.8 [44.9-48.6]) and HS4 (25.6 [23.4-27.7]), respectively. Conclusion: This study generated utility values for HS vignettes describing symptoms, functioning, and HRQoL for patients with cGvHD receiving 3L therapy. The utility values highlighted a substantial burden of cGvHD and HRQoL impact associated with the treatment response level. However, assessing concordance between utility estimates derived from the vignette-based method in a general population and those from patients with cGvHD is further warranted.