Social/economic costs and health-related quality of life in patients with Prader-Willi syndrome in Europe

Psychometric Properties of the EQ-5D-Y-5L for Children With Intellectual Disability

OBJECTIVES

The EQ-5D-Y-5L is a generic preference-based measure of health-related quality of life for children. This study aimed to describe the distributional properties, test-retest reliability, and convergent validity of the EQ-5D-Y-5L in children with intellectual disability (ID).

METHODS

Caregivers of children with ID (aged 4 to 18 years) completed an online survey, including a proxy-report EQ-5D-Y-5L, the Quality-of-life Inventory-Disability, and disability-appropriate measures corresponding to the EQ-5D dimensions: mobility, self-care (SC), usual activities (UA), pain/discomfort (PD), and worry/sadness/unhappiness. Twenty-one participants repeated the EQ-5D-Y-5L a few weeks later. Test-retest reliability was computed using weighted kappa and intraclass correlation coefficients, and convergent validity using Spearman's and Pearson's correlation coefficients.

RESULTS

Caregivers of 234 children completed the survey, with <1% missing values. Only 1.7% reported "no problems" on all dimensions (11111). The dimensions with the lowest percentage of "no problems" were SC and UA (both 8%). Test-retest reliability coefficients were fair to substantial for 4 dimensions (weighted kappa .30 to .79) but low for PD and overall health, as measured by the visual analog scale (EQ-VAS). Convergent validity was strong (Spearman's correlation .65 to .87) for mobility, SC, and PD; moderate to strong for worry/sadness/unhappiness (.47 to .60) and the EQ-VAS (Pearson's correlation .49); and weak to moderate for UA (.21 to .52).

CONCLUSIONS

Convergent validity was generally good; test-retest reliability varied. Children with ID had lower scores on SC and UA than other populations, and their EQ-VAS could fluctuate greatly, indicating poorer and less stable health-related quality of life.

Prader-Willi syndrome in a large sample from Spain: general features, obesity and regular use of psychotropic medication

BACKGROUND

Prader-Willi syndrome (PWS), a genetically determined disorder, the most frequent cause of early onset obesity, is associated with physical and cognitive dysfunctions and behavioural disturbances; these disturbances are frequently treated with psychotropic medication. The aim of this cross-sectional study was to describe the characteristics of the first large national sample of persons with PWS in Spain and analyse the relationships of those characteristics with key demographic and clinical factors, particularly with obesity and the regular use of psychotropic medication.

METHODS

Participants were recruited among all members of the Spanish Prader-Willi Association who agreed to take part in the study and fulfilled its inclusion criteria. Family and patient demographic features, family size and birth order, intelligence quotient (IQ), anthropometric measures, lifestyle habits, behavioural disturbances (with the Aberrant Behavior Checklist) and clinical data, as well as use of psychotropic drugs and their side effects (with the UKU scale), were collected in genetically confirmed cases of PWS. Bivariate and logistic regression analyses were used for determining the associations of demographic and clinical factors with both obesity and the regular use of psychotropic medication.

RESULTS

The cohort included 177 participants (aged 6-48 years), that is, 90 (50.8%) males and 87 (49.2%) females. Behavioural disturbances were present in a range of 75% to 93% of participants; psychotropic medication was prescribed to 81 (45.8%) of them. Number of siblings showed a direct correlation with IQ, especially among males, and inappropriate speech was more intense in only-child females. Obesity was, in parallel, strongly associated with ascending age and with not being currently under growth hormone (GH) treatment. Participants taking any psychotropic medication were characterised by more frequent age ≥30 years, high level of hyperactivity and a psychiatric diagnosis.

CONCLUSIONS

Characterisation of persons with PWS in Spain confirms their physical and behavioural phenotype and supports the long-term application of GH therapy and the rational use of psychotropic medication.

How Well Does the EQ-5D-Y-5L Describe Children With Intellectual Disability?: "There's a Lot More to My Child Than That She Can't Wash or Dress Herself."

OBJECTIVES

The EQ-5D-5L is a generic health utility instrument for measuring health-related quality of life (HRQoL), with self-report and proxy report versions for children (EQ-5D-Y-5L). Children with intellectual disability (ID) are a heterogeneous population whose impairments and comorbidities place them at risk of poor HRQoL. This study aimed to describe the content validity and suitability for children with ID of a proxy report version of the EQ-5D-Y-5L as seen by their caregivers.

METHODS

A proxy report EQ-5D-Y-5L was administered to caregivers of children with ID. Using cognitive think-aloud interviewing, participants were encouraged to provide the reasoning for their choices, assess the questions' relevance, comprehensibility, and comprehensiveness, and comment on the tool's strengths and weaknesses. Qualitative content analysis used both directed (deductive) and conventional (inductive) methods.

RESULTS

There were 28 interviews with 30 caregivers of children with ID (aged 8-22 years, 17 boys, with autism spectrum disorder, cerebral palsy, Down syndrome, and rare genetic disorders). The EQ-5D-Y-5L was considered clear, concise, and largely relevant, but insufficiently comprehensive for this population. Interviewees sought clarification of the definition of HRQoL, whether it included unchanging impairments (vs fluctuating health states), and what basis of comparison to use (child or peer). Many interviewees suggested inclusion of questions for other domains, including communication and social engagement, equipment and human supports required, and a wider range of mental health questions.

CONCLUSIONS

The study suggests that further work is required to ensure accurate responses to the EQ-5D-Y-5L from caregivers of children with ID and to describe these children adequately.

Methods used to account for caregivers' sex and gender within studies examining the financial burden of caregivers of children and adolescents : Results from a scoping review

Background

Interest in the financial burden of informal caregivers has been growing. Unfortunately, it remains unclear which method(s) should be used when quantifying this burden.

Purpose

We conducted a scoping review aimed at identifying which methods have been used to conduct such work and quantified their performance. We were also interested in examining how sex and gender considerations were considered within selected studies.

Data Sources

Using a standardized approach, we identified studies published between 2012 and 2022 that aimed to document the financial burden of caregivers to child and adolescent patients. Our search strategy was applied to the MEDLINE, Embase, CINHAL, and Academic Search Premier databases.

Study Selection

Manuscript selection was performed by pairs of reviewers.

Data Extraction

Data extraction was performed by one reviewer with a second reviewer performing quality control. Results were reported using a narrative approach.

Data Synthesis

We identified 9801 unique citations, of which 200 were included in our review. Selected studies covered various disease area (eg, infection/parasitic diseases [n = 31, 16%]) and included quantitative (n = 180, 90%), qualitative (n = 4, 2%) and mixed study designs (n = 16, 8%). Most studies (n = 182, 91%) used questionnaires/surveys, either alone or in combination with other methods, to assess caregivers' financial burden. Less than half (n = 93, 47%) of studies reported on caregivers' sex and none reported on their gender.

Conclusion

We conducted an unrestricted review of published studies examining caregiver's financial burden which allowed us to identify general methodological trends observed in this literature. We believe this work may help improve future studies focusing on this important issue.

Are We Capturing the Socioeconomic Burden of Rare Genetic Disease? A Scoping Review of Economic Evaluations and Cost-of-Illness Studies

BACKGROUND AND OBJECTIVES

Rare diseases have a significant impact on patients, families, the health system, and society. Measuring the socioeconomic burden is crucial to valuing interventions for rare diseases. Healthcare system costs are significant, but so are costs to other government sectors, patients, families, and society. To understand the breadth of costs captured in rare disease studies, we examined the cost categories and elements of socioeconomic burden captured in published studies.

METHODS

A scoping review was conducted using five electronic databases to identify English language economic evaluations and cost-of-illness studies of interventions for rare diseases (2011-21). We mapped costs using a previously developed evidence-informed framework of socioeconomic burden costs for rare disease.

RESULTS

Of 4890 studies identified, 48 economic evaluations and 22 cost-of-illness studies were included. While 18/22 cost-of-illness studies utilized a societal perspective, only 7/48 economic evaluations incorporated societal costs. Most reported cost categories related to medical costs, with medication and hospitalizations being the most common elements for both study designs. Costs borne by patients, families, and society were reported less among economic evaluations than cost-of-illness studies. These included: productivity (10% vs 77%), travel/accommodation (6% vs 68%), government benefits (4% vs 18%), and family impacts (0% vs 50%).

CONCLUSIONS

Contrary to cost-of-illness analyses, most of the included economic evaluations did not account for the hidden burden of rare diseases, that is, costs borne by patients, families, and societies. Including these types of costs in future studies would provide a more comprehensive picture of the burden of disease, providing empirical data to inform how we value and make decisions regarding rare disease interventions, health policy, and resource allocation.

Health-related quality of life and medication use among individuals with Angelman syndrome

PURPOSE

The primary goal of this analysis is to describe the health-related quality of life (HRQoL), medical history, and medication use among adolescents and adults individuals with Angelman syndrome (AS).

METHODS

The analysis uses baseline data collected during the STARS study, a double-blind placebo controlled trial of gaboxadol (OV101) in adolescents and adults with AS. The HRQoL was estimated using EuroQoL 5-Dimension 5-Level (EQ-5D) health questionnaire proxy 1 version, which was completed by the caregivers. EQ-5D consists of two parts, a 5-dimension descriptive and a visual analogue scale (VAS) component. The utility score derived from EQ-5D ranges from 0 to 1 (perfect health) and VAS ranges from 0 to 100 (perfect health).

RESULTS

87 individuals with AS were included in the present analysis. The mean utility score was 0.44 ± 0.20 and VAS score was 84 ± 1.5. The EQ-5D data indicated that the self-care, mobility and daily activities were most impacted. All adolescents (100%) and most adults (93%) had at least moderate problems with self-care activities, such as washing or dressing themselves. More than half (55%) of the adolescents and adults had at least moderate issues with mobility and usual activities. Approximately, 30% of adolescents and adults had moderate to extreme problems with anxiety/depression. High baseline concomitant use of medications was observed across both age groups with an average of 5 medications being used per person.

CONCLUSION

This study highlights the impact of AS on HRQoL and medication utilization among adolescents and adults individuals with AS.

Progressive resistance training in young people with Prader-Willi syndrome: protocol for a randomised trial (PRESTO)

INTRODUCTION

Preliminary evidence suggests that progressive resistance training may be beneficial for people with Prader-Willi Syndrome (PWS), a rare genetic condition that results in muscle weakness and low muscle tone.To establish whether community-based progressive resistance training is effective in improving the muscle strength of people with PWS; to determine cost-effectiveness; and, to complete a process evaluation assessing intervention fidelity, exploring mechanisms of impact, understanding participant experiences and identifying contextual factors affecting implementation.

METHODS AND ANALYSIS

A multisite, randomised controlled trial will be completed. Sixty participants with PWS will be randomised to receive either progressive resistance training (experimental) or non-progressive exercise (placebo control). Participants will be aged 13 to 60 years, be able to follow simple instructions in English and have no contraindications to performing progressive resistance training. The experimental group will complete progressive resistance training two times weekly for 24 weeks supervised by an exercise professional at a community gym. The control group will receive all aspects of the intervention except progressive overload. Outcomes will be assessed at week 25 (primary endpoint) and week 52 by a blinded assessor. The primary outcome is muscle strength assessed using one repetition maximum for upper limb and lower limb. Secondary outcomes are muscle mass, functional strength, physical activity, community participation, health-related quality of life and behaviour. Health economic analysis will evaluate cost-effectiveness. Process evaluation will assess safety and intervention fidelity, investigate mechanism of impact, explore participant experiences and identify contextual factors affecting implementation. Data collection commenced in February 2020 and will conclude in September 2023.

ETHICS AND DISSEMINATION

Ethical approval was obtained from The Royal Children's Hospital Human Research Ethics Committee (HREC/50874/RCHM-2019) under the National Mutual Acceptance initiative. Research governance approvals were obtained from five clinical sites. Results will be disseminated through published manuscripts, conference presentations, public seminars and practical resources for stakeholder groups.

TRIAL REGISTRATION NUMBER

ACTRN12620000416998; Australian and New Zealand Clinical Trial Registry.

Rare disease emerging as a global public health priority

The genomics revolution over the past three decades has led to great strides in rare disease (RD) research, which presents a major shift in global policy landscape. While RDs are individually rare, there are common challenges and unmet medical and social needs experienced by the RD population globally. The various disabilities arising from RDs as well as diagnostic and treatment uncertainty were demonstrated to have detrimental influence on the health, psychosocial, and economic aspects of RD families. Despite the collective large number of patients and families affected by RDs internationally, the general lack of public awareness and expertise constraints have neglected and marginalized the RD population in health systems and in health- and social-care policies. The current Coronavirus Disease of 2019 (COVID-19) pandemic has exposed the long-standing and fundamental challenges of the RD population, and has reminded us of the critical need of addressing the systemic inequalities and widespread disparities across populations and jurisdictions. Owing to the commonality in goals between RD movements and universal health coverage targets, the United Nations (UN) has highlighted the importance of recognizing RDs in policies, and has recently adopted the UN Resolution to promote greater integration of RDs in the UN agenda, advancing UN's commitment in achieving the 2030 Sustainable Development Goals of "leav[ing] no one behind." Governments have also started to launch Genome Projects in their respective jurisdictions, aiming to integrate genomic medicine into mainstream healthcare. In this paper, we review the challenges experienced by the RD population, the establishment and adoption of RD policies, and the state of evidence in addressing these challenges from a global perspective. The Hong Kong Genome Project was illustrated as a case study to highlight the role of Genome Projects in enhancing clinical application of genomic medicine for personalized medicine and in improving equity of access and return in global genomics. Through reviewing what has been achieved to date, this paper will provide future directions as RD emerges as a global public health priority, in hopes of moving a step toward a more equitable and inclusive community for the RD population in times of pandemics and beyond.

Evaluating the Health-Related Quality of Life of the Rare Disease Population in Hong Kong Using EQ-5D 3-Level

OBJECTIVES

This study aimed to establish a normative profile of health-related quality of life (HRQOL) of the rare disease (RD) population in Hong Kong (HK) and identify potential predictors.

METHODS

Between March 2020 and October 2020, patients with RD and caregivers were recruited through Rare Disease Hong Kong, the largest RD patient group alliance in HK. HRQOL was derived using the EQ-5D 3-Level with reference to the established HK value set. Utility scores were stratified according to demographics and disease-related information. Multiple linear regression was performed to explore the associations between patient characteristics and HRQOL.

RESULTS

A total of 286 patients, covering 107 unique RDs, reported a mean utility score of 0.53 (SD 0.36). Thirty patients (10.5%) reported negative utility scores, indicating worse-than-death health states. More problems were recorded in the "usual activities" and "self-care" dimensions. Univariate analyses revealed that neurologic diseases, high out-of-pocket expenditure, home modification, and living in public housing or subdivided flats/units were significantly associated with lower HRQOL. A total of 99 caregivers reported a mean utility score of 0.78 (SD 0.17), which was significantly associated with the utility score of patients they took care of (r = 0.32; P = .001).

CONCLUSIONS

The normative profile of the RD population was established, which revealed lower HRQOL in the RD population than other chronic disease groups and general population in HK. Findings were corroborated by evidence from other cohorts using EQ-5D, combined as part of a meta-analysis. Identifying predictors highlight areas that should be prioritized to improve HRQOL of RD population through clinical and psychosocial dimensions.

Valuing the "Burden" and Impact of Rare Diseases: A Scoping Review

Introduction: Rare diseases (RDs) are a severe, chronic, degenerative and often life-threatening group of conditions affecting more than 30 million people in Europe. Their impact is often underreported and ranges from psychological and physical symptoms seriously compromising quality of life. There is then a need to consolidate knowledge on the economic, social, and quality of life impacts of rare diseases.

Methods: This scoping review is the result of 9 qualitative interviews with experts and a literature search on Cost-of-Illness (COI) studies and quality of life (QoL) studies following the PRISMA methodology. Grey literature was also included to complement findings. Results. 63 COI studies were retrieved, covering 42 diseases and a vast majority of them using a prevalence-based approach (94%). All studies included medical costs, while 60% included non-medical costs, 68% productivity losses and 43% informal care costs. 56 studies on QoL were retrieved, mostly from Europe, with 30 different measurement tools. Grey literature included surveys from the pharmaceutical industry and patient organisations.

Discussion: The majority of studies evaluating the impact of RDs on the individual and society use the COI approach, mostly from a societal perspective. Studies often vary in scope, making them difficult to consolidate or compare results. While medical costs and productivity losses are consistently included, QoL aspects are rarely considered in COI and are usually measured through generic tools.

Conclusion: A comprehensive study on impact of rare disease across countries in Europe is lacking. Existing studies are heterogeneous in their scope and methodology and often lack a holistic picture of the impact of rare. Consensus on standards and methodology across countries and diseases is then needed. Studies that consider a holistic approach are often conducted by pharmaceutical companies and patient organisations exploring a specific disease area but are not necessarily visible in the literature and could benefit from the sharing of standards and best practices.

Pediatric growth hormone treatment in Italy: A systematic review of epidemiology, quality of life, treatment adherence, and economic impact

Objectives

This systematic review aims to describe 1) the epidemiology of the diseases indicated for treatment with growth hormone (GH) in Italy; 2) the adherence to the GH treatment in Italy and factors associated with non-adherence; 3) the economic impact of GH treatment in Italy; 4) the quality of life of patients treated with GH and their caregivers in Italy.

Methods

Systematic literature searches were performed in PubMed, Embase and Web of Science from January 2010 to March 2021. Literature selection process, data extraction and quality assessment were performed by two independent reviewers. Study protocol has been registered in PROSPERO (CRD42021240455).

Results

We included 25 studies in the qualitative synthesis. The estimated prevalence of growth hormone deficiency (GHD) was 1/4,000–10,000 in the general population of children; the prevalence of Short Stature HOmeoboX Containing gene deficiency (SHOX-D) was 1/1,000–2,000 in the general population of children; the birth prevalence of Turner syndrome was 1/2,500; the birth prevalence of Prader-Willi syndrome (PWS) was 1/15,000. Treatment adherence was suboptimal, with a range of non-adherent patients of 10–30%. The main reasons for suboptimal adherence were forgetfulness, being away from home, pain/discomfort caused by the injection. Economic studies reported a total cost for a complete multi-year course of GH treatment of almost 100,000 euros. A study showed that drug wastage can amount up to 15% of consumption, and that in some Italian regions there could be a considerable over- or under-prescribing. In general, patients and caregivers considered the GH treatment acceptable. There was a general satisfaction among patients with regard to social and school life and GH treatment outcomes, while there was a certain level of intolerance to GH treatment among adolescents. Studies on PWS patients and their caregivers showed a lower quality of life compared to the general population, and that social stigma persists.

Conclusion

Growth failure conditions with approved GH treatment in Italy constitute a significant burden of disease in clinical, social, and economic terms. GH treatment is generally considered acceptable by patients and caregivers. The total cost of the GH treatment is considerable; there are margins for improving efficiency, by increasing adherence, reducing drug wastage and promoting prescriptive appropriateness.

Rare Neurological Diseases: an Overreview of Pathophysiology, Epidemiology, Clinical Features and Pharmacoeconomic Considerations in the Treating

Rare diseases (RD) are serious chronic diseases affecting small number of people compared to the general population. There are between 6000 and 8000 RDs, which affect about 400 million people worldwide. Drugs used for causal treatment of RDs are called orphan drugs. RDs bear great clinical and economic burden for patients, their families, healthcare systems and society overall. There are at least two reasons for the high cost of treatment of RDs. First, there is no causal therapy for majority of RDs, so exacerbations, complications, and hospitalizations in those patients are common. The second reason is high price of available orphan drugs, which are not cost-effective when traditional pharmacoeconomic evaluation is employed. The pharmacoeconomic aspect of the treatment of RDs is especially important in the field of neurology, since at least one fifth of all RDs is composed of neurological conditions. The aim of this paper was to provide a concise overview of the pathophysiological, epidemiological and clinical characteristics of some of the most important and common rare neurological diseases, with special reference to their impact on society and economy.

What Every Internist-Endocrinologist Should Know about Rare Genetic Syndromes in Order to Prevent Needless Diagnostics, Missed Diagnoses and Medical Complications: Five Years of 'Internal Medicine for Rare Genetic Syndromes'

Patients with complex rare genetic syndromes (CRGS) have combined medical problems affecting multiple organ systems. Pediatric multidisciplinary (MD) care has improved life expectancy, however, transfer to internal medicine is hindered by the lack of adequate MD care for adults. We have launched an MD outpatient clinic providing syndrome-specific care for adults with CRGS, which, to our knowledge, is the first one worldwide in the field of internal medicine. Between 2015 and 2020, we have treated 720 adults with over 60 syndromes. Eighty-nine percent of the syndromes were associated with endocrine problems. We describe case series of missed diagnoses and patients who had undergone extensive diagnostic testing for symptoms that could actually be explained by their syndrome. Based on our experiences and review of the literature, we provide an algorithm for the clinical approach of health problems in CRGS adults. We conclude that missed diagnoses and needless invasive tests seem common in CRGS adults. Due to the increased life expectancy, an increasing number of patients with CRGS will transfer to adult endocrinology. Internist-endocrinologists (in training) should be aware of their special needs and medical pitfalls of CRGS will help prevent the burden of unnecessary diagnostics and under- and overtreatment.

Health-Related Quality of Life in Patients With Different Diseases Measured With the EQ-5D-5L: A Systematic Review

Background: The EQ-5D-5L is a generic preference-based questionnaire developed by the EuroQol Group to measure health-related quality of life (HRQoL) in 2005. Since its development, it has been increasingly applied in populations with various diseases and has been found to have good reliability and sensitivity. This study aimed to summarize the health utility elicited from EQ-5D-5L for patients with different diseases in cross-sectional studies worldwide.

Methods: Web of Science, MEDLINE, EMBASE, and the Cochrane Library were searched from January 1, 2012, to October 31, 2019. Cross-sectional studies reporting utility values measured with the EQ-5D-5L in patients with any specific disease were eligible. The language was limited to English. Reference lists of the retrieved studies were manually searched to identify more studies that met the inclusion criteria. Methodological quality was assessed with the Agency for Health Research and Quality (AHRQ) checklist. In addition, meta-analyses were performed for utility values of any specific disease reported in three or more studies.

Results: In total, 9,400 records were identified, and 98 studies met the inclusion criteria. In the included studies, 50 different diseases and 98,085 patients were analyzed. Thirty-five studies involving seven different diseases were included in meta-analyses. The health utility ranged from 0.31 to 0.99 for diabetes mellitus [meta-analysis random-effect model (REM): 0.83, (95% CI = 0.77–0.90); fixed-effect model (FEM): 0.93 (95% CI = 0.93–0.93)]; from 0.62 to 0.90 for neoplasms [REM: 0.75 (95% CI = 0.68–0.82); FEM: 0.80 (95% CI = 0.78–0.81)]; from 0.56 to 0.85 for cardiovascular disease [REM: 0.77 (95% CI = 0.75–0.79); FEM: 0.76 (95% CI = 0.75–0.76)]; from 0.31 to 0.78 for multiple sclerosis [REM: 0.56 (95% CI = 0.47–0.66); FEM: 0.67 (95% CI = 0.66–0.68)]; from 0.68 to 0.79 for chronic obstructive pulmonary disease [REM: 0.75 (95% CI = 0.71–0.80); FEM: 0.76 (95% CI = 0.75–0.77)] from 0.65 to 0.90 for HIV infection [REM: 0.84 (95% CI = 0.80–0.88); FEM: 0.81 (95% CI = 0.80–0.82)]; from 0.37 to 0.89 for chronic kidney disease [REM: 0.70 (95% CI = 0.48–0.92; FEM: 0.76 (95% CI = 0.74–0.78)].

Conclusions: EQ-5D-5L is one of the most widely used preference-based measures of HRQoL in patients with different diseases worldwide. The variation of utility values for the same disease was influenced by the characteristics of patients, the living environment, and the EQ-5D-5L value set.

Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42020158694.

Quantifying the Burden of Hyperphagia in Prader-Willi Syndrome Using Quality-Adjusted Life-years

BACKGROUND

Prader-Willi syndrome (PWS) is a rare disease associated with cognitive impairment, hypotonia, hyperphagia (an insatiable hunger), and obesity. Therapies that target hyperphagia are in development, but understanding the value of these therapies to inform patient-focused drug development (PFDD) requires valid data on disease burden. We estimated disease burden by measuring and comparing quality-adjusted life-years (QALYs) for 3 PWS health states relevant to current PFDD initiatives.

METHODS

Time trade-off (TTO) and a visual analog scale (VAS) were used to elicit PWS caregivers' values for 3 fixed health states for a standardized patient described with (1) untreated PWS, (2) PWS with controlled obesity, and (3) PWS with controlled obesity and hyperphagia. We excluded participants who left at least 1 TTO or VAS question blank or incomplete (noncompleters) and respondents who reported the same answer for all TTO scenarios (nontraders). The remaining group of respondents (traders) were used for all primary analyses. We assessed validity and bias of QALY estimates by comparing differences in health state valuations, treatment priorities, and characteristics among respondents who did and did not complete the TTO.

RESULTS

A total of 458 respondents completed the survey, including 226 traders, 93 nontraders, and 139 noncompleters. Traders valued untreated PWS at 0.69 QALYs, PWS with controlled obesity at 0.79 QALYs, and controlled hyperphagia/obesity at 0.91 QALY (P < 0.01 for differences among health state values). Reported VAS ratings were similar for traders versus nontraders for untreated PWS (38.64 vs 38.95, P = 0.89) and PWS with controlled obesity (57.36 vs 55.14, P = 0.35) but varied for PWS with controlled obesity and hyperphagia (70.70 vs 64.46, P = 0.02). Exclusion of noncompleters did not introduce obvious bias because traders and noncompleters were similar in treatment priorities and characteristics. The exclusion of nontraders did not meaningfully alter mean or distribution of valuations.

CONCLUSIONS

This study found that avoiding hyperphagia decreases the burden of PWS and that these results are robust, even once imposing strict inclusion criteria. Use of fixed health states to estimate QALYs addresses many of the complexities of measuring disease burden in rare and pediatric conditions, indicating the potential value of this approach to inform premarket decision makers in identifying outcome importance. (Clin Ther. 2021;XX:XXX-XXX) © 2021 Elsevier HS Journals, Inc.

Cost-of-illness studies in rare diseases: a scoping review

Objective

The aim of this scoping review was to overview the cost-of-illness studies conducted in rare diseases.

Methods

We searched papers published in English in PubMed from January 2007 to December 2018. We selected cost-of-illness studies on rare diseases defined as those with prevalence lower than 5 per 10,000 cases. Studies were selected by one researcher and verified by a second researcher. Methodological characteristics were extracted to develop a narrative synthesis.

Results

We included 63 cost-of-illness studies on 42 rare diseases conducted in 25 countries, and 9 systematic reviews. Most studies (94%) adopted a prevalence-based estimation, where the predominant design was cross-sectional with a bottom-up approach. Only four studies adopted an incidence-based estimation. Most studies used questionnaires to patients or caregivers to collect resource utilisation data (67%) although an important number of studies used databases or registries as a source of data (48%). Costs of lost productivity, non-medical costs and informal care costs were included in 68%, 60% and 43% of studies, respectively.

Conclusion

This review found a paucity of cost-of-illness studies in rare diseases. However, the analysis shows that the cost-of-illness studies of rare diseases are feasible, although the main issue is the lack of primary and/or aggregated data that often prevents a reliable estimation of the economic burden.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-021-01815-3.

Cost-of-illness studies in rare diseases: a scoping review

OBJECTIVE

The aim of this scoping review was to overview the cost-of-illness studies conducted in rare diseases.

METHODS

We searched papers published in English in PubMed from January 2007 to December 2018. We selected cost-of-illness studies on rare diseases defined as those with prevalence lower than 5 per 10,000 cases. Studies were selected by one researcher and verified by a second researcher. Methodological characteristics were extracted to develop a narrative synthesis.

RESULTS

We included 63 cost-of-illness studies on 42 rare diseases conducted in 25 countries, and 9 systematic reviews. Most studies (94%) adopted a prevalence-based estimation, where the predominant design was cross-sectional with a bottom-up approach. Only four studies adopted an incidence-based estimation. Most studies used questionnaires to patients or caregivers to collect resource utilisation data (67%) although an important number of studies used databases or registries as a source of data (48%). Costs of lost productivity, non-medical costs and informal care costs were included in 68%, 60% and 43% of studies, respectively.

CONCLUSION

This review found a paucity of cost-of-illness studies in rare diseases. However, the analysis shows that the cost-of-illness studies of rare diseases are feasible, although the main issue is the lack of primary and/or aggregated data that often prevents a reliable estimation of the economic burden.

Characteristics and relationship between hyperphagia, anxiety, behavioral challenges and caregiver burden in Prader-Willi syndrome

Objectives

Prader-Willi syndrome (PWS) is a rare genetic disorder characterized by maladaptive behaviors, amongst which hyperphagia is a life-long concern for individuals with PWS and their caregivers. The current study examined the contribution of hyperphagia and other factors to caregiver burden across lifespan, in 204 caregivers of individuals with PWS living in the US, using the Zarit Burden Interview (ZBI) and the hyperphagia questionnaire (HQ-CT).

Results

We found a strong relationship between ZBI and HQ-CT especially in individuals with PWS older than 4 y and showed that HQ-CT scores of individuals with PWS is positively correlated with ZBI scores of their caregivers. The weight status of individuals with PWS was not associated with HQ-CT and ZBI scores, except for obese individuals who had significantly higher HQ-CT scores when compared to normal weight PWS individuals. We looked at PWS symptoms and care-related issues that impacted individuals and caregivers the most. We found that care-related tasks had the biggest negative impact on caregivers of children aged 0–4 y, whereas anxiety, temper tantrums, and oppositional behaviors of older individuals with PWS had the biggest impact on their caregivers concomitant with their high caregiver burden. Finally, we assessed the variability of HQ-CT and ZBI over 6 months in a subgroup of 83 participants. Overall, neither measure differed between 6 months and baseline. Most individual’s absolute HQ-CT score changes were between 0–2 units, whereas absolute ZBI score changes were between 0–6 points. Changes in the caregiver’s or individual’s life had little or no effect on HQ-CT and ZBI scores.

Conclusions

This study demonstrates a relationship between hyperphagia and caregiver burden and sheds light on predominant symptoms in children and adolescents that likely underly PWS caregiver burden. The stability and relationship between HQ-CT and ZBI support ZBI as an additional outcome measure in PWS clinical trials.

Societal costs and burden of hereditary transthyretin amyloidosis polyneuropathy

Background: Hereditary transthyretin amyloidosis polyneuropathy (ATTRv-PN) is a rare life-threatening disease that imposes considerable mortality and morbidity associated with increased costs, high social support and productivity losses. This study aims to estimate the societal costs and burden of ATTRv-PN.Methods: A cost-of-illness (COI) and burden of disease model were specified from a societal perspective, using a prevalence-based approach. Direct and indirect costs were included. Healthcare resource use was retrieved from public databases, previous Portuguese studies and the literature. The burden of disease was expressed in terms of disability-adjusted life years (DALYs), as defined by the World Health Organisation.Results: In 2016, the total annual COI of ATTRv-PN in Portugal was 52,502,796€ and the mean cost per patient was 28,152€ (79% direct; 21% indirect costs). Treatments accounted for 52% of total costs, while 0.18% were devoted to disease prevention. A total of 2056 DALYs were lost, 26% due to disability and 74% due to death.Conclusions: Annual costs and burden of ATTRv-PN were considerable but within the range of other rare diseases. Policies and public interventions to prevent and reduce the burden of disease should be prioritised, since patients experience excess morbidity, mortality and total costs will likely increase in the future.

Analysis of economic burden and its associated factors of twenty-three rare diseases in Shanghai

Background

It is estimated that at present there are over 10 million rare disease patients in China. Recently an increased focus from policy perspective has been placed on rare diseases management. Improved disease definitions and the releases of local and national rare disease lists are some of the steps taken already. Despite these developments, few Chinese rare disease-related epidemiology and economic studies exist, thus hindering assessment of the true burden of rare diseases. For a rare disease with an effective treatment, this is a particularly important aspect due to the often-high cost associated.

Objective

The goal of this study is to address the data scarcity on the subject of rare diseases economic impact in China. We aim to address an existing knowledge gap and to provide a timely analysis of the economic burden of 23 rare diseases in Shanghai, China.

Methods

We utilized the data from the Health Information Exchange system of Shanghai and employed statistical modeling to analyze the economic burden of rare diseases with an effective treatment in Shanghai.

Results

First, we described the actual direct medical expenditure and analyzed its associated factors. Second, we found age, disease type, number of complications, and payment type were significantly associated with rare disease medical direct costs. Third, a generalized linear model was employed to estimate the annual direct cost. The mean direct medical cost was estimated as ¥9588 (US$1521) for inpatients and ¥1060 (US$168) for outpatients, and was over ¥15 million (~US$2.4 million) per year overall.

Conclusion

Our study is one of the first quantifying the economic burden of an extensive set of rare diseases in Shanghai and China. Our results can serve to inform healthcare-focused policy making, contribute to the increase of public awareness, and incentivize development of rare-disease strategies and treatments specific to the Chinese context.

Electronic supplementary material

The online version of this article (10.1186/s13023-019-1168-4) contains supplementary material, which is available to authorized users.

Quality of life in caregivers of young children with Prader-Willi syndrome

BACKGROUND

This study aimed to measure quality of life (QOL) in primary caregivers of young childrenwith Prader-Willi syndrome (PWS).

METHODS

The caregivers of 32 children aged from 6.1 to 71.2 months completed the Chinese version of the World Health Organization Quality of Life-BREF (WHOQOL-BREF). We also evaluated the social adaption capacity of these children with Infants-Junior Middle School Students' Social-Life Abilities Scale. Correlation test was used to explore the related factors to caregivers' QOL.

RESULTS

Caregivers of young children with PWS had significantly lower QOL. The correlation analyses revealed that caregivers' QOL was lower in children with young age, combined diseases or symptoms or poor social adaption, or caregivers having concerns about the child.

CONCLUSIONS

Rearing a chilld with PWS may lead to decreased QOL. Psychological status of caregivers should be highlighted and social support should be given to families with PWS children.

Cost-of-illness studies in nine Central and Eastern European countries

BACKGROUND

To date, a multi-country review evaluating the cost-of-illness (COI) studies from the Central and Eastern European (CEE) region has not yet been published. Our main objective was to provide a general description about published COI studies from CEE.

METHODS

A systematic search was performed between 1 January 2006 and 1 June 2017 in Medline, EMBASE, The Cochrane Library, CINAHL, and Web of Science to identify all relevant COI studies from nine CEE countries. COI studies reporting costs without any restrictions by age, co-morbidities, or treatment were included. Methodology, publication standards, and cost results were analysed.

RESULTS

We identified 58 studies providing 83 country-specific COI results: Austria (n = 9), Bulgaria (n = 16), Croatia (n = 3), the Czech Republic (n = 10), Hungary (n = 24), Poland (n = 11), Romania (n = 3), Slovakia (n = 3), and Slovenia (n = 4). Endocrine, nutritional, and metabolic diseases (18%), neoplasms (12%), infections (11%), and neurological disorders (11%) were the most frequently studied clinical areas, and multiple sclerosis was the most commonly studied disease. Overall, 57 (98%) of the studies explicitly stated the source of resource use data, 45 (78%) the study perspective, 34 (64%) the costing method, and 24 (58%) reported at least one unit costs. Regardless of methodological differences, a positive relationship was observed between costs of diseases and countries' per capita GDP.

CONCLUSIONS

Cost-of-illness studies varied considerably in terms of methodology, publication practice, and clinical areas. Due to these heterogeneities, transferability of the COI results is limited across Central and Eastern European countries.

Caregiver priorities for endpoints to evaluate treatments for Prader-Willi syndrome: a best-worst scaling

OBJECTIVES

Prader-Willi syndrome (PWS) is a rare genetic disorder associated with varying degrees of hyperphagia, obesity, intellectual disability, and anxiety across the affected individuals' lifetimes. This study quantified caregiver priorities for potential treatment endpoints to identify unmet needs in PWS.

METHODS

The authors partnered with the International Consortium to Advance Clinical Trials for PWS (PWS-CTC) and a diverse stakeholder advisory board to develop a best-worst scaling instrument. Seven relevant endpoints were assessed using a balanced incomplete block design. Caregivers were asked to determine the most and least important of a sub-set of four endpoints in each task. Caregivers were recruited nationally though patient registries, email lists, and social media. Best-worst score was calculated to determine caregiver priorities; ranging from 0 (least important) to 10 (most important). A novel kernel-smoothing approach was used to analyze caregiver endpoint priority variations with relation to age of the PWS individual.

RESULTS

In total, 457 caregivers participated in the study. Respondents were mostly parents (97%), females (83%), and Caucasian (87%) who cared for a PWS individual ranging from 4-54 years. Caregivers value treatments addressing hyperphagia (score = 7.08, SE = 0.17) and anxiety (score = 6.35, SE = 0.16) as most important. Key variations in priorities were observed across age, including treatments targeting anxiety, temper outbursts, and intellectual functions.

CONCLUSIONS

This study demonstrates that caregivers prioritize hyperphagia and, using a novel method, demonstrates that this is independent of the age of the person with PWS. This is even the case for parents of young children who have yet to experience hyperphagia, indicating that these results are not subject to a hypothetical bias.

The feasibility of using the EQ-5D-3L with adults with mild to moderate learning disabilities within a randomized control trial: a qualitative evaluation

Background

In trials incorporating a health economic evaluation component, reliable validated measures for health-related quality of life (HRQOL) are essential. The EQ-5D is the preferred measure for cost-effectiveness analysis in UK trials. This paper presents a qualitative evaluation of the use of the EQ-5D-3L in a feasibility randomised control trial with participants who had a mild- to  moderate learning disability and type 2 diabetes.

Methods

Researchers administered the EQ-5D-3L to 82 participants at baseline and 77 at follow-up. After each interview, researchers rated the ease of administering the EQ-5D-3L and made free-text entries on the administration experience. For a subset of 16 interviews, researchers audio-recorded more detailed journal entries. Ease of administration data were analysed using descriptive statistics. Free-text responses were subject to a basic content analysis. The EQ-5D-3L-related journal entries were transcribed, coded and analysed thematically.

Results

Over half of participants were perceived to experience difficulty answering some or all of the items in the EQ-5D-3L (60% at baseline; 54% at follow-up). Analysis of the free-text entries and audio journals identified four themes that question the use of the EQ-5D-3L in this population. The first theme is related to observations of participant intellectual ability and difficulties, for example, in understanding the wording of the measure. Theme 2 is related to the normalisation of adjustments for impairments, which rendered the measure less sensitive in this population. Theme 3 is related to researcher adaptation and non-standard administration. An overarching fourth theme was identified in that people with learning disabilities were viewed as ‘unreliable witnesses’ by both researchers and supporters.

Conclusions

It is recommended that the EQ-5D-3L should not be used in isolation to assess health-related quality of life outcomes in trials research in adults with a learning disability. Further research is required to develop and evaluate a version of the EQ-5D appropriate for this population in trials research. It is unrealistic to expect that adjustments to the wording alone will deliver an appropriate measure: supporter or researcher involvement will almost always be required. This requirement needs to be factored into the development and administration guidelines of any new version of the EQ-5D for adults with a learning disability.

Trial registration

Current Controlled Trials ISRCTN41897033 [registered 21 January 2013].

Electronic supplementary material

The online version of this article (10.1186/s40814-018-0357-6) contains supplementary material, which is available to authorized users.

DIFFERENTIATION OF HEALTH-RELATED QUALITY OF LIFE OUTCOMES BETWEEN FIVE DISEASE AREAS: RESULTS FROM AN INTERNATIONAL SURVEY OF PATIENTS

OBJECTIVES

Health-related quality of life (HRQoL) data generated by generic, preference-based instruments (i.e., EQ-5D) are highly demanded in health policy decision making, because they allow for direct comparisons of HRQoL outcomes between disease areas. We aimed to quantify HRQoL outcomes in breast cancer (BC), rheumatoid arthritis (RA), multiple sclerosis (MS), rare cancers (RC), and rare disease (RD) patients and understand the patterns that differentiate HRQoL outcomes between these disease areas, and more specifically between rare and more common disease population groups.

METHODS

An international, Web survey of patients measured HRQoL (EQ-5D-5L), self-perceived health (EQ-5D-5L Visual Analogue Scale), and additional QoL dimensions, such as patient disability level.

RESULTS

We received 675 completed responses. Average utility loss was 53.5 percent, 32.5 percent, and 33.3 percent for RD, RA, and MS patients, respectively, in contrast to 18.6 percent for BC and RC patients. Statistically significant differences (p < .05) were observed between disease groups in all EQ-5D-5L domain outcomes, apart from that of "Anxiety/Depression." Severe and/or extreme problems were reported in performing usual activities for RD and RC (34 percent and 13 percent of overall problems reported respectively), mobility for MS (18 percent), pain/discomfort for RA (13 percent), and anxiety/depression for BC (7 percent) patients.

CONCLUSIONS

We demonstrated significant differences in the dimensions that drive HRQoL outcomes between rare and more common diseases and showcased that the same EQ-5D utility may reflect very different severities depending on the patient population under investigation. Future research should examine whether outcomes in other, critical HRQoL domains not included in generic measures also highlight significant differences across disease areas.

High levels of caregiver burden in Prader-Willi syndrome

Objectives

Prader-Willi syndrome (PWS) is a rare genetic neurodevelopmental disorder that is characterized by hyperphagia, developmental delay, incomplete sexual development, mild-to-moderate intellectual disability, and a variety of challenging behavioral and psychiatric symptoms. The characteristics of PWS can be difficult for caregivers to cope with and are likely to cause significant and long- term caregiver burden. The current study examined burden in 142 caregivers of children and adults with PWS living in the US using the Zarit Burden Interview (ZBI). The study aimed to measure the level of burden in caregivers of individuals with PWS, to explore the impact of PWS on caregiver quality of life, and to assess ZBI as an indicator of that impact.

Results

Caregivers participating in this study were predominantly mothers, 30–59 years old, non-Hispanic Whites, married or in a relationship, with an annual household income slightly distributed towards higher income. Nearly 90% of the caregiver`s children with PWS lived at home. Caregivers experienced high caregiver burden with an average ZBI score of 44.4 ± 15.4. ZBI scores were highest for caregivers of teenage and young adult individuals with PWS (49.2 ± 14.6 and 49.2 ± 14.1, respectively), while those caring for older adults (>30) and the youngest age group had lower scores (38.6 ±10.5 and 34.8 ±12.5, respectively). Caregivers reported that caring for a person with PWS negatively impacted their romantic relationship, ability to work, sleep, and mood. Whereas we did not find strong correlations between family income or level of help the caregiver receives and ZBI scores, the results showed significant correlations and a linear relationship between ZBI scores and caregiver depressed mood, feelings of anxiety, negative romantic relationship impact, as well as sleep and work disruption.

Conclusions

Our study reveals that PWS incurs high caregiver burden and impacts many aspects of the lives of caregiver. We identified the ZBI as a good predictor of that impact. Our findings draw attention to the critical unmet need for support for caregivers of individuals with PWS.

AZP-531, an unacylated ghrelin analog, improves food-related behavior in patients with Prader-Willi syndrome: A randomized placebo-controlled trial

Context and objective

Prader-Willi syndrome (PWS) is characterized by early-onset hyperphagia and increased circulating levels of the orexigenic Acylated Ghrelin (AG) hormone with a relative deficit of Unacylated Ghrelin (UAG). AZP-531, a first-in-class UAG analog, was shown to inhibit the orexigenic effect of AG in animals, to improve glycemic control and decrease body weight in humans. We aimed to investigate the safety and efficacy of AZP-531 in patients with PWS for whom no approved treatment for hyperphagia is currently available.

Methods and design

Multi-center, randomized, double-blind, placebo-controlled trial. Forty-seven patients with genetically confirmed PWS and evidence of hyperphagia received daily subcutaneous injections of AZP-531 (3 and 4 mg for 50–70 kg and >70 kg body weight, respectively) or matching placebo for 14 days. Assessments included adverse events, vital signs, safety laboratory tests, the Hyperphagia Questionnaire (HQ), patient-reported appetite, body composition and glycemic measures.

Results

AZP-531 was well tolerated. There was a significant improvement with AZP-531 versus placebo in the mean total score, the 9-item score and the severity domain score of the HQ (p < .05). The highest reduction in the total and 9-item scores was observed in AZP-531 subjects with the highest hyperphagia score at baseline. Findings were supported by a reduction in appetite scores observed with AZP-531 only. Body weight did not change in both groups while a significant reduction in waist circumference and fat mass was observed only with AZP-531. AZP-531 significantly decreased post-prandial glucose levels in a baseline glucose dependent fashion.

Conclusions

AZP-531 may constitute a new treatment strategy to improve hyperphagia and metabolic issues in patients with PWS. These findings support further investigation in longer-term clinical trials.

Social/economic costs and health-related quality of life in patients with spinal muscular atrophy (SMA) in Spain

BACKGROUND

The aim of this study was to determine the economic burden and health-related quality of life (HRQOL) of patients with Spinal Muscular Atrophy (SMA) and their caregivers in Spain.

METHODS

This was a cross-sectional and retrospective study of patients diagnosed with SMA in Spain. We adopted a bottom up, prevalence approach design to study patients with SMA. The patient's caregivers completed an anonymous questionnaire regarding their socio-demographic characteristics, use of healthcare services and non-healthcare services. Costs were estimated from a societal perspective (including healthcare costs and non-healthcare costs), and health-related quality of life (HRQOL) was assessed using the EQ-5D questionnaire. The main caregivers also answered a questionnaire on their characteristics and on their HRQOL.

RESULTS

A total of 81 caregivers of patients with different subtypes of SMA completed the questionnaire. Based on the reference unitary prices for 2014, the average annual costs per patient were € 33,721. Direct healthcare costs were € 10,882 (representing around 32.3% of the total cost) and the direct non-healthcare costs were € 22,839 (67.7% of the total cost). The mean EQ-5D social tariff score for patients was 0.16, and the mean score of the EQ-5D visual analogue scale was 54. The mean EQ-5D social tariff score for caregivers was 0.49 and their mean score on the EQ-5D visual analogue scale was 69.

CONCLUSION

The results highlight the burden that SMA has in terms of costs and decreased HRQOL, not only for patients but also for their caregivers. In particular, the substantial social/economic burden is mostly attributable to the high direct non-healthcare costs.