Extracting homogenous data from heterogenous diseases: RaraSwed, the Swedish national rare disease quality registry.

In the Swedish universal healthcare system, persons living with rare diseases (PLWRD) face major challenges in receiving diagnosis and accessing care,stemming in part from heterogeneity of disease and systemic barriers to care. This contributes to health inequity and a lack of visibility for PLWRD within thehealth system. This Perspective paper provides an overview of the facilitators and challenges during the development and implementation of a national raredisease (RD) quality registry, RaraSwed. The registry collects data on RD diagnosis. Adopting a social innovation and systems thinking methodology, inaddition to governance, have proven beneficial. RaraSwed supports RD research, evidence-based RD care, and Sweden's National Quality Policy and Strategy(NQPS) for RD. Future modules on patient-reported and physician-reported data on care coordination, treatment and clinical attributes will capture the holisticpatient experience. RaraSwed may contribute to health equity for PLWRD in Sweden and in turn facilitate international RD data harmonisation.