Defining Utility Values for Chorea Health States in Patients with Huntington's Disease

Health state utility estimates for value assessments of novel treatments in Huntington's disease: a systematic literature review

BACKGROUND

Huntington's disease (HD) is a progressive neurodegenerative disease with a devastating impact on patients and their families. Quantifying how treatments affect patient outcomes is critical for informing reimbursement decisions. Many countries mandate a formal value assessment in which the treatment benefit is measured as quality-adjusted life-years, calculated with the use of utility estimates that reflect respondents' preferences for health states.

OBJECTIVE

To summarize published health state utility data in HD and identify gaps and uncertainties in the data available that could be used to inform value assessments.

METHODS

We conducted a systematic literature review of studies that used preference-based instruments (e.g., EQ-5D and SF-6D) to estimate utility values for people with HD. The studies were published between January 2012 and December 2022.

RESULTS

Of 383 articles screened, 16 articles reported utility values estimated in 11 distinct studies. The utility measure most frequently reported was EQ-5D (9/11 studies). Two studies reported SF-6D data; one used time trade-off methods to value health state descriptions (vignettes). Although utility scores generally worsened to a lower value with increased HD severity, the estimates varied considerably across studies. The EQ-5D index range was 0.89 - 0.72 for mild/prodromal HD and 0.71 - 0.37 for severe/late-stage disease.

CONCLUSIONS

This study uncovered high variability in published utility estimates, indicating substantial uncertainty in existing data. Further research is needed to better understand preferences and valuation across all stages and domains of HD symptoms and the degree to which generic utility measures capture the impact of cognitive changes on quality of life.

Predictors of persistence and adherence to deutetrabenazine among patients with Huntington disease or tardive dyskinesia

Introduction

Deutetrabenazine is approved for treatment of Huntington disease (HD)-related chorea and tardive dyskinesia (TD) in adults. Factors associated with deutetrabenazine persistence and adherence are not well understood.

Methods

Claims data from the Symphony Health Solutions Integrated Dataverse (2017-2019) were analyzed to identify real-world predictors of deutetrabenazine persistence and adherence in adults with HD or TD in the United States. Predictive models for persistence and adherence that considered patient demographics, payer type, comorbidities, treatment history, and health care resource use were developed.

Results

In HD, use of anticonvulsants (HR = 2.00 [95% CI = 1.03, 3.85]; P < .05), lipid-lowering agents (2.22 [1.03, 4.76]; P < .05), and Medicaid versus Medicare insurance (2.27 [1.03, 5.00]; P < .05) predicted persistence, whereas only comorbid anxiety disorders predicted discontinuation (0.46 [0.23, 0.93]; P < .05). Of these patients, 62.5% were adherent at 6 months. Use of ≤2 treatments for chronic diseases (OR = 0.18 [95% CI = 0.04, 0.81]; P < .05) and Medicaid versus Medicare insurance (0.27 [0.09, 0.75]; P < .05) was associated with lower odds of adherence. In TD, use of lipid-lowering agents (HR = 4.76 [95% CI = 1.02, 20.00]; P < .05) predicted persistence, while comorbid schizoaffective disorder and/or schizophrenia (0.16 [0.14, 0.69]; P < .05) and sleep-wake disorders (0.18 [0.04, 0.82]; P < .05) predicted discontinuation. Of these patients, 46.7% were adherent at 6 months. Comorbid schizoaffective disorder and/or schizophrenia was associated with lower odds of adherence (OR = 0.26 [0.07, 0.91]; P < .05).

Discussion

Identifying factors predictive of discontinuation and/or nonadherence to deutetrabenazine may facilitate the development of personalized support programs that seek to improve outcomes in patients with HD or TD.