Recruitment procedures for descriptive socio-economic studies in rare diseases. The BURQOL-RD project

Measurement of Health-Related Quality of Life in Individuals With Rare Diseases in China: Nation-Wide Online Survey

BACKGROUND

Rare diseases (RDs) affect millions of people worldwide, and these diseases can severely impact the health-related quality of life (HRQoL) of those affected. Despite this, there is a lack of research measuring HRQoL using the EQ-5D-5L, which is one of the most widely used generic preference-based instruments to measure HRQoL in populations living with RDs.

OBJECTIVE

This study aimed to measure HRQoL using the EQ-5D-5L in a large number of patients with various types of RDs in China, and to examine the relationship between respondents' socioeconomic characteristics and preference-based health utility scores.

METHODS

The data used in this study were obtained from a web-based survey conducted in China. The survey aimed to explore and understand the health and socioeconomic status of patients with RDs in China. We recruited registered and eligible members, including patients or their primary caregivers, from 33 RD patient associations to complete the questionnaires via their internal social networks. HRQoL was measured using the EQ-5D-5L utility score, which was calculated based on an established Chinese value set. Utility scores have been presented based on demographics and disease-related information. Univariate linear regression analysis was used to assess the differences in the EQ-5D-5L utility scores between subgroups.

RESULTS

A total of 12,502 respondents completed the questionnaire and provided valid responses, including 6919 self-completed respondents and 5583 proxy-completed respondents. Data from 10,102 participants over the age of 12 years were elicited for analysis. Among patients with RDs, 65.3% (6599/10,102), 47.5% (4799/10,102), 47.0% (4746/10,102), 24.8% (2506/10,102), and 18.4% (1855/10,102) reported no problems for "self-care," "usual activities," "mobility," "pain/discomfort," and "anxiety/depression," respectively. A full health state was reported by 6.0% (413/6902) and 9.2% (295/3200) of self- and proxy-completed patients, respectively. Among self-completed patients, 69.9% (4826/6902) and 50.4% (3478/6902) reported no problems for "self-care" and "usual activities," respectively, whereas only 17.7% (1223/6902) reported problems for "anxiety/depression." Proxy-completed respondents showed a higher proportion of reporting extreme problems than self-completed respondents in all 5 dimensions. The mean utility scores reported by self- and proxy-completed respondents were 0.691 and 0.590, respectively. Different types of caregivers reported different utility scores, and among them, proxy-completed (mother) respondents reported the highest mean utility score.

CONCLUSIONS

The establishment of a normative profile for RD patients can facilitate patients' adaptation and assess the effectiveness of interventions to improve the HRQoL and well-being of this population. Differences between self- and proxy-completed HRQoL assessed by the EQ-5D-5L have been identified in this study. This finding highlights the importance of incorporating perspectives from both patients and their proxies in clinical practice. Further development of the patient cohort is necessary to assess long-term changes in HRQoL in the RD population.

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.

Epidemiology of Rare Lung Diseases: The Challenges and Opportunities to Improve Research and Knowledge

Rare lung diseases encompass a broad spectrum of conditions and affect an estimated 1.2-2.5 million people in North America and 1.5-3 million people in Europe. While individual rare lung diseases affect less than 1 in 2000 individuals, collectively they have a significant impact upon the population at large. Hence it is vital to understand firstly the epidemiology and subsequently the pathogenesis and clinical course of these disorders. Through a greater understanding of these aspects of disease, progress can be made in reducing symptoms, containing healthcare costs and utilizing resources efficiently. Furthermore, a greater understanding of the pathobiology of rare lung diseases can inform both the pathogenesis and management of more common pulmonary disorders.In this chapter we review how epidemiological approaches and the utilization of patient registries has improved the knowledge and management of rare lung diseases. We further focus on the epidemiology of several of the more widely known rare pulmonary disorders, including idiopathic pulmonary fibrosis (IPF), cystic fibrosis (CF) and alpha-1 antitrypsin deficiency (AATD). To conclude we describe how patient advocacy groups and foundations have driven advances in research and management of ultra-rare lung diseases, namely, the major strides made in the management and understanding of lymphangioleiomyomatosis (LAM) and pulmonary alveolar proteinosis (PAP).We conclude that the models used to study some of the rarest of diseases may be successfully adopted by other rare and common disease communities, leading to improved care and the possibility of novel therapeutic options.

Cost-of-Illness in Rare Diseases

Cost-of-illness (COI) studies quantify the economic burden of a disease, including direct healthcare and non-healthcare costs and productivity losses. Different approaches can be adopted to evaluate the resources associated to a disease and to calculate the total costs. Prevalence-based studies estimate the total costs of a disease during a given period, while incidence-based studies measure lifetime costs from onset until death. Data can be collected from individuals, using a bottom-up approach, or from population statistics, using a top-down approach. Different perspectives are possible, but the broadest and also mostly used is the societal one. Appropriate discounting should be applied for future costs and a sensitivity analyses of main parameters should be performed. The main limitation of COI studies is that they don't account the outcomes or benefits of possible treatments.There is a lack of COI studies in the field of rare diseases. A multinational COI study (BURQOL-RD) evaluated recently the burden of 10 rare diseases in Europe, using a prevalence-based method with a bottom-up approach to quantify resources from a societal perspective, which is the mostly used methodology for COI studies in rare diseases; however, several other studies illustrate different approaches to conduct COI analysis in this field, such as incidence-based methods or narrower perspectives.COI studies are useful to inform policy-makers about the magnitude of a disease. To support correctly the decision-making process, it is necessary to identify the cost-drivers through COI studies with robust design and standardized methodology.