Current status of specific pediatric chronic diseases in Japan: National measures, disease types, treatment availability, copayment assistance, and research.

In Japan, specific pediatric chronic diseases include 788 diseases in 16 groups of diseases, 278 categories, and 845 subcategories as of November 1, 2021. The national specific pediatric chronic diseases measures - also called the Medical Aid Program for Chronic Pediatric Diseases of Specified Categories (MAPChD) - was established in Japan in 1974 and enshrined in law in 2005. Patients with specific pediatric chronic diseases can receive government support and welfare in several ways: MAPChD requires diagnosis and medical treatment at designated hospitals and by designated physicians so that patients receive optimal treatment; the copayment rate for medical expenses is reduced to 20% and a maximum is set depending on household income; and the analysis of specific pediatric chronic diseases from different perspectives is continuously being promoted. In addition to these three aspects, various measures are being implemented to provide ongoing support for patients with specific pediatric chronic diseases as they grow up.