Rare is frequent and frequent is costly: rare diseases as a challenge for health care systems

Excerpt

Of 30,000 known diseases about 6,000–7,000 are defined as rare diseases, also commonly known as orphan diseases [1]. Within the European Union (EU), rare diseases are specified as indications with a prevalence of less than 5 out of 10,000 [2]. In other jurisdictions, different critical prevalence rates prevail when it comes to the classification of rare diseases: the United States (US) 7.5, Japan 4 and Australia 1.2 patients per 10,000 in a population [3]. Although the number of patients in each rare disease indication is low, the aggregated number of patients living with a rare disease is large. Many of them do not know that they are affected by a rare disease and are still searching for a diagnosis or therapy. In total, the prevalence of all rare diseases is approximately 5 %, which equals, for instance, about half of the prevalence of diabetes. Therefore, experts assume that 400 million people worldwide are rare-disease patients. Focusing on the EU, 27–36 million people suffer from rare diseases. Within the USA, there is an estimated prevalence of approximately 25 million US citizens [4]. Only within Germany, approximately 4 million patients suffer from a rare disease [5]. This adds up to a paradox of rarity. Many rare diseases are associated with a significant negative effect on life expectancy and quality of life. As a considerable number of those diseases are caused by gene mutations, many patients are children suffering from a hereditary disease. Treating patients with rare diseases is not uncommon for physicians. However, in many cases, care providers are not aware of the fact that they are medicating a rare disease. …