Development of a Patient-reported Outcome to Measure the Health-related Quality of Life of Children, Adolescents and Young Adults With Cystinosis

What this Trial Is About

Cystinosis is a rare inherited metabolic disorder causing cystine to build up in many organs, initially affecting kidney function in children and potentially leading to kidney failure by early school age if untreated. As patients live longer due to treatments, other organs like eyes, muscles, endocrine organs, and the central nervous system may also be affected. This study aims to develop a patient-reported outcome measure (PROM) to assess the quality of life specifically for children, adolescents, and young adults with cystinosis in several languages including German, English, Spanish, and French. The development of this PROM will occur in three phases with participants from Germany, the United States, Spain, and France. It starts with focus interviews involving young patients aged 8 to 26 and their parents, followed by pilot testing and cognitive debriefing of the initial instrument. Finally, a field test and retest will be conducted to refine the questionnaire. Different age groups will have tailored versions, and the instrument will include parent-reporting for children aged 0 to 26. Participants will complete interviews and questionnaires assessing various aspects of their quality of life. The study includes repeated testing to check reliability, with questionnaires completed again after two weeks by a subset of participants. Researchers will also use established generic quality of life tools alongside the new cystinosis-specific PROM. The study runs from 2022 to mid-2025 and aims to produce a validated, easy-to-use tool for research and patient care.

Development of Health-related Quality of Life Instrument for Patients With Cystinosis