Utility Assessment of Moderate to Severe Thyroid Eye Disease Health States

Abstract

Importance: Thyroid eye disease (TED) results in varying degrees of proptosis and diplopia negatively affecting quality of life (QoL), producing possibly substantial visual changes, disfigurement, and disability. Objective: To determine the association of varying TED severities with QoL in a non-TED population by assessing health state utility scores. Design, Setting, and Participants: This qualitative study, conducted from April 20, 2020, to April 29, 2021, assessed health states for active, moderate-severe TED, and values were elicited using time trade-off methods. Six health states of varying severity were determined from 2 placebo-controlled clinical trials (171 patients with TED and clinical activity score ≥4, ±diplopia/proptosis) and refined using interviews with US patients with TED (n = 6). Each health state description was validated by interviews with additional TED patient advocates (n = 3) and physician experts (n = 3). Health state descriptions and a QOL questionnaire were piloted and administered to a general population. Visual analog scales (VASs) were also administered to detect concurrence of the findings. Main Outcomes and Measures: TED health state utility scores and whether they differ from one another were assessed using Shapiro-Wilk, Kruskal-Wallis, pairwise Wilcoxon rank sum, and paired t tests. Results: A total of 111 participants completed time trade-off interviews. The mean (SD) utility value was 0.44 (0.34). The lowest (worse) mean utility value was observed in the most severe disease state (constant diplopia/large proptosis) with 0.30 (95% CI, 0.24-0.36), followed by constant diplopia/small proptosis (0.34; 95% CI, 0.29-0.40), intermittent or inconstant diplopia/large proptosis (0.43; 95% CI, 0.36-0.49), no diplopia/large proptosis (0.46; 95% CI, 0.40-0.52), and intermittent or inconstant diplopia/small proptosis (0.52; 95% CI, 0.45-0.58). The highest (best) mean value, 0.60 (95% CI, 0.54-0.67), was observed for the least severe disease state (no diplopia/small proptosis). Conclusions and Relevance: These findings suggest that patients with active, moderate-severe TED may have substantial disutility, with increasing severity of proptosis/diplopia more likely to have detrimental associations with QoL. These health state scores may provide a baseline for determining QoL improvement in these TED health states (utility gains) treated with new therapies..