Understanding the Burdens Associated with Huntington’s Disease in Manifest Patients and Care Partners–Comparing to Parkinson’s Disease and the General Population

Health-related quality of life in Parkinson's disease: systematic review and meta-analysis of EuroQol (EQ-5D) utility scores

INTRODUCTION

Evaluating the Health-related quality of life (HRQoL) of individuals with Parkinson's disease (PD) holds significant importance in clinical and research settings. The EQ-5D is a widely recognized tool for comprehensive measurement of HRQoL using utility values. This study aims to systematically review and synthesize EQ-5D utility values from existing literature on patients with PD and their caregivers.

METHODS

We conducted a systematic search for studies that provided EQ-5D utility scores for patients with PD, using PubMed-Medline, Scopus, and Embase and selected the studies. The selected studies underwent systematic review, including an assessment of their quality. We performed a meta-analysis using a random-effect model and conducted a meta-regression analysis to investigate sources of heterogeneity among the studies.

RESULTS

The search result of 13,417 articles that were reviewed, 130 studies with 33,914 participants were selected for systematic review, and 79 studies were included for meta-analysis. The pooled EQ-5D utility values and visual analog score (VAS) among PD were 62.72% (60.53-64.93, I2 = 99.56%) and 0.60 (0.55-0.65, I2 = 99.81%), respectively. The pooled scores for caregivers' EQ-VAS and EQ-5D utility were 70.10% (63.99-76.20, I2 = 98.25%) and 0.71 (0.61-0.81, I2 = 94.88%), respectively. Disease duration (P < 0.05) showed a negative correlation with EQ-5D utility values on meta-regression.

CONCLUSION

The pooled utility values of PD and their caregivers help to understand their HRQoL and aid in conducting health economics research. The negative association between disease duration and utility values highlights the evolving nature of HRQoL challenges, suggesting the need for appropriate long-term disease management.

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.

Disparities in Huntington Disease Severity: Analysis Using the ENROLL-HD Dataset

Background and Objectives

Social and structural determinants of health (SDOH) have been associated with disability in neurologic diseases. However, the association between these factors and disability in Huntington disease (HD) has not been studied. This study aimed to evaluate the association of racial and sociodemographic factors with disease severity in patients with HD in North America.

Methods

We conducted a cross-sectional study of genetically confirmed participants with HD (36+ CAG repeats) in the North American region using the ENROLL-HD 2020 periodic dataset. In this analysis, our exposure variable was the participant's race/ethnicity. The main outcome measure was disease severity, as measured by the Total Functional Capacity Score (TFC), which measures the level of disability of patients with HD. We used multivariate regression models to adjust for sociodemographic factors that may mediate or moderate a causal effect between race/ethnicity and disease severity.

Results

Among 4,717 gene-positive participants in the North American region, 89.5% identified as White, 3.4% as Hispanic or Latino, and 2.3% as African American/Black. The average TFC score was 10.22 (SD 3.22); 48% of participants completed either secondary education (including college) or a professional degree, and 55% lived in a city and not in a town, village, or rural location. In multivariate regression models, we found that Black participants and those with less than a high school degree entered the ENROLL-HD study with lower TFC scores than White participants. We also found that compared with those with at least a high school degree, those who completed some form of higher education or professional degree had higher TFC scores (p < 0.001). This multivariate analysis did not find an association between geographic location and TFC score.

Discussion

Our study found that Black participants in North America presented to ENROLL-HD with more advanced disease than White patients. We also found that higher education was associated with less advanced disease when entering the ENROLL-HD study. The role of race/ethnicity and education in HD symptom severity warrants further investigation. These findings underscore the importance of further studying the role of social and structural determinants of health in patients with HD, particularly those from historically marginalized communities.

Interleukin-6 as a marker of Huntington's disease progression: Systematic review and meta-analysis

Huntington's disease (HD) is a rare, inherited disorder with a broad spectrum of manifestations that vary with disease severity and progression. Although genetic testing can readily confirm the initial diagnosis of HD, markers sensitive to HD progression are needed to aid the development of individual treatment plans. The current analysis aims to identify plasma Interleukin-6 (IL-6) as a marker of disease progression in HD patients. A systematic search of PubMed and Medline from conception through October 2021 was conducted. Studies reporting plasma IL-6 levels of mutation-positive HD patients and healthy controls that met inclusion criteria were selected. The search strategy collected 303 studies, 9 of which met analysis inclusion criteria. From included studies, plasma IL-6 levels of 469 individuals with the HD mutation and 206 healthy controls were collected. Plasma IL-6 levels were meta-analytically compared between healthy controls and individuals with the confirmed HD mutation at all stages of disease and correlated to performance on standardized measures of total cognitive and motor function. Plasma IL-6 was significantly increased in HD groups compared to controls (g = 0.73, 95% CI = 0.31,1.16, P < 0.01) and increased significantly throughout most stages of disease progression, notably between pre-manifest and manifest (g = 0.31, 95% CI = 0.04,0.59, P < 0.05) and early and moderate HD stages (g = 0.52, 95% CI = 0.18,0.86, P < 0.01). Significant correlations between plasma IL-6 levels and HD symptomatic progression were identified, with increased cytokine levels associated with more severe motor impairments (r = 0.179, 95% CI = 0.0479,0.304, P = 0.008) and more extreme disabilities in activities of daily living and/or work tasks (r = -0.229, 95% CI = -0.334, -0.119, P < 0.001). Conclusively, plasma IL-6 levels correlate with disease and motor symptom progression and may act as a viable marker for clinical use. Analysis is limited by small study numbers and highlights the need for future work to identify definitive ranges or rates of change of plasma IL-6 levels that correlate to progressive HD disease states.

Quality of life, health-related quality of life, and associated factors in Huntington's disease: a systematic review

BACKGROUND

Huntington's disease (HD) is a genetic, neurodegenerative disease. Due to the progressive nature of HD and the absence of a cure, (health-related) quality of life ((HR)QoL) is an important topic. Several studies have investigated (HR)QoL in HD, yet a clear synthesis of the existing literature is lacking to date. We performed a systematic review on self-reported (HR)QoL, and factors and intervention effects associated with (HR)QoL in premanifest and manifest HD gene expansion carriers (pHDGECs and mHDGECs, respectively).

METHODS

PubMed, EMBASE, Web of Science, and PsycINFO were searched systematically from September 17th, 2021, up to August 11th, 2022. Methodological and conceptual quality of the included studies was assessed with two appraisal tools.

RESULTS

30 out of 70 eligible articles were included. mHDGECs experienced lower (HR)QoL compared to pHDGECs and controls, whereas mixed findings were reported when compared to other neurological diseases. Several factors were associated with (HR)QoL that might contribute to lower (HR)QoL in mHDGECs, including depressive symptoms, physical and psychological symptoms, lower functional capacity, lower support, and unmet needs. Multidisciplinary rehabilitation programs and a respiratory muscle training were beneficial for (HR)QoL in mHDGECs.

DISCUSSION

(HR)QoL is experienced differently across the course of the disease. Although (HR)QoL is key for understanding the impact of HD and the effect of symptomatic treatment, there is a need to improve the methodological and conceptual shortcomings that were found in most studies, especially regarding the conceptual clarity when reporting on QoL and HRQoL. Suggestions for strengthening these shortcomings are provided in this review.

An Overview of Specialist Services for Huntington's Disease in the United Kingdom

BACKGROUND

Huntington's disease (HD) is a rare inherited neurodegenerative disorder characterized by complex evolving needs that change as the condition progresses. There is limited understanding about the organization of HD clinical services and their resourcing in the United Kingdom (UK).

OBJECTIVE

To understand the organization and resourcing of specialist HD services for people with HD (PwHD) in the UKMethods:This cross-sectional study collected quantitative data via on online survey, and qualitative data via telephone semi-structured interviews. Descriptive statistics were used to describe quantitative outcomes, and qualitative results were analyzed using content analysis.

RESULTS

A total of 31 specialist services for HD were identified. Of the 27 services that completed the online survey, 23 had an active multidisciplinary team of healthcare professionals (HCPs) and were led primarily by a mental health trust (26%) or tertiary referral hospital (26%). Specialist services offered outpatient clinics (96%), outreach in the community (74%), telemedicine (70%), inpatient beds (26%) and satellite clinics (26%). Many services indicated that their capacity (ability to see patients as often as needed with current resources) was difficult, with some services reporting more difficulty at the early or later stages of HD. Key resourcing gaps were identified with access to facilities, HCPs and referral networks.

CONCLUSIONS

This research highlights the variation in organization and capacity within individual HD services as well as current resourcing and gaps in access that influence this capacity. Further research should be done to understand the impact of service organization and current resourcing gaps in access on the quality of care provided for PwHD in the UK.

An Overview of Specialist Services for Huntington's Disease in the United Kingdom

BACKGROUND

Huntington's disease (HD) is a rare inherited neurodegenerative disorder characterized by complex evolving needs that change as the condition progresses. There is limited understanding about the organization of HD clinical services and their resourcing in the United Kingdom (UK).

OBJECTIVE

To understand the organization and resourcing of specialist HD services for people with HD (PwHD) in the UKMethods:This cross-sectional study collected quantitative data via on online survey, and qualitative data via telephone semi-structured interviews. Descriptive statistics were used to describe quantitative outcomes, and qualitative results were analyzed using content analysis.

RESULTS

A total of 31 specialist services for HD were identified. Of the 27 services that completed the online survey, 23 had an active multidisciplinary team of healthcare professionals (HCPs) and were led primarily by a mental health trust (26%) or tertiary referral hospital (26%). Specialist services offered outpatient clinics (96%), outreach in the community (74%), telemedicine (70%), inpatient beds (26%) and satellite clinics (26%). Many services indicated that their capacity (ability to see patients as often as needed with current resources) was difficult, with some services reporting more difficulty at the early or later stages of HD. Key resourcing gaps were identified with access to facilities, HCPs and referral networks.

CONCLUSIONS

This research highlights the variation in organization and capacity within individual HD services as well as current resourcing and gaps in access that influence this capacity. Further research should be done to understand the impact of service organization and current resourcing gaps in access on the quality of care provided for PwHD in the UK.