Challenges in Japan's dual systems of support for pediatric and adult intractable diseases

Japan has developed two separate frameworks to support patients with chronic and rare diseases: the Specified Pediatric Chronic Diseases (SPCD) Program and the Designated Intractable Diseases (DID) System. Although both aim to provide medical and social assistance, they differ in age of eligibility, diseases covered, and administrative procedures. The SPCD Program provides support to individuals under 18 years of age (extendable to 20) with 858 eligible conditions, whereas the DID System, with 348 designated diseases, applies to all ages. These structural discrepancies create a critical policy gap when pediatric patients transition into adulthood. Those whose conditions are not listed under the DID System lose their eligibility for public subsidies, resulting in sudden financial strain and reduced social participation. Additional issues include inconsistencies in diagnostic criteria, limited access to transitional care facilities -currently established in only 12 prefectures -and insufficient family-centered support, especially for siblings acting as young carers. To achieve continuity of care and equity, Japan must harmonize disease definitions and transition criteria, introduce temporary relief measures for non-designated patients, increase the number of Transitional Care Support Centers in regions, and institutionalize family-inclusive assistance. Establishing a seamless policy framework over a patient's life will not only encourage patients' independence but also strengthen the sustainability of Japan's healthcare system in the face of an aging population.