Rare Disease Definition
- A rare disease occurs infrequently in a population, but there is no universal definition. 3 elements to the definition as used in various countries are as follows:
- The total number of people having the disease
- Its prevalence
- Non-availability of treatment for the disorder
- A formal definition helps a nation to identify such diseases that require financial support for the discovery and development of drugs and biologics.This in turn helps in encouraging the product development improving the funding for basic and clinical research on rare diseases.
- The World Health Organization (W.H.O.) has suggested that a rare disease should be defined as one with frequency less than 6.5 – 10 per 10,000 people
- In USA, it is defined as any disease or condition that affects less than 200,000 persons.
- The affected numbers in Japan are 50,000 people, 20,000 in Korea ,10,000 in Taiwan and 2000 in Australia .
- In China, rare disorder is defined as one that affects less than 1/500,000 people or one that has a neonatal morbidity of less than 1/10,000.
- Stated as the prevalence per 10,000, the number used in USA is 7.5, in Europe it is 5, in Japan it is 4, in South Korea it is 4, Australia it is 1.1 and Taiwan it is 1.0.
- Thus, a country defines a rare disease most appropriate in the context of its own population, health care system and resources.
- India, like many developing countries, currently has no standard definition. Considering the large population of India, ORDI suggests a disease to be defined as rare if it affects 1 in 5,000 people or less.