Towards a better understanding of rare diseases

Rare diseases are defined variably across the world. In the EU, they are ‘diseases that affect less than 1 in 2000 people’. Whichever definition you use, only a very few people may be affected by any one of these rare conditions, but collectively these patients form a significant group that require health services. Yet these patients face barriers in accessing care and treatments, often due to a lack of knowledge about specific diseases.

Underpinning research including information on the numbers of affected individuals, disease progression, and impact of treatment is essential for health professionals and service providers to ensure appropriate services and treatments are developed. However, obtaining this information can be a challenge due to the rare, widely dispersed and heterogeneous nature of these diseases. Cases tend to be few and far-between, precluding the gathering of robust data to support evidence-based conclusions.

What is the value of rare disease registries?

Registries can help overcome some of these challenges through a concerted effort to gather information on affected individuals. They can act as a source of standardised information about a group of patients with a shared condition. This data – which can cover epidemiology of the disease (e.g. incidence and prevalence) as well as progression and natural history of the disease through monitoring and evaluation of patient outcomes - is invaluable to health authorities in planning services and to researchers in advancing scientific understanding and developing effective treatments. For rare diseases – where generally relevant information can be scarce and fragmented – well managed registries can be a powerful framework for collating and consolidating information.

The value of rare disease registries has been recognised for some time by the rare disease community and policy makers. Indeed, creation of national rare disease registries is seen as an important part of rare disease policy plans, not least the UK’s own Strategy for Rare Diseases. Implementation of this strategy includes provision by Public Health England (PHE) of NCARDRS – the National Congenital Anomaly and Rare Disease Registration Service - which will provide a comprehensive national registration service for all congenital anomalies and rare diseases diagnosed and treated in England. 

A registry of registries

The landscape of rare disease registries is a complex one. Registries are set up by different groups - researchers/clinicians, commercial companies, or patients - each with different objectives in mind, and this impacts on the information they collect and their coverage (from regional to global). In addition there may be more than one registry for particular disease and information about particular patients may be present in more than one registry due to the differing objectives of the registry. All this makes for a highly complex and inefficient landscape, presenting challenges for researchers wishing to access data for analysis. Moreover, the dispersal of data makes it difficult for its utilisation for public health purposes, which often require pooling of data.

The EU is attempting to address the fragmented nature of rare disease registries by creating a registry of registries, platforms for connecting databases and providing recommendations on data collection. However, guidance at the national level for those setting up registries relating to such issues is scant. This lack of guidance can result in duplication of registries, or in registries lacking functionality or being used in suboptimal ways. It can also lead to failure in securing sufficient longer-term funding to support their sustainability. Without the capability for long-term maintenance, rare disease registries are unlikely to be able to collate the volume and detail of data that makes for an effective resource.

Towards better utilisation of data on rare diseases

The value of data, especially in relation to rare disease, is optimal only when it can be easily collated and shared. The current fragmented landscape is leading to duplication of effort and valuable data is siloed and inaccessible. To overcome these barriers will involve enabling all those involved in data generation, collation and analysis to understand their place in the landscape and their relationship to other registries in order that they can contribute in their fullest capacity. This can also help identify areas where more effort is needed in relation to data generation or analysis.

An efficient system of rare disease registries can facilitate research around earlier diagnosis, testing and treatment. PHG Foundation is undertaking a project to describe the current landscape of rare disease registries. Ultimately, our aim is to support the building of health systems that give patients real opportunities to make informed decisions about their care and future health.