Rare diseases have such a low prevalence that special organisation of the patient care pathway is required to address them. In France, the implementation of specific cystic fibrosis (CF) centres [1] has improved the care pathway of CF patients. Indeed, early diagnosis and progress in usual routine treatment might have contributed to improving the prognosis of CF [2]. In the light of this success, rare respiratory diseases reference centres (CRMR: "centre de Références des Maladies Respiratoires Rares") were created from 2007 under the framework of the national plan for rare diseases. The ear, nose and throat (ENT), pneumology and paediatrics departments at our hospital (CHIC: "Centre hospitalier intercommunal de Créteil") have a long-standing expertise in the diagnosis and treatment of primary ciliary dyskinesia (PCD) [3,4]. A reference centre for rare respiratory diseases (CRMR-RESPIRARE-Site Créteil) was accredited in 2017.In the present study, we aimed to assess the impact of the opening of the CRMR on the care of PCD patients and their lung function. This is a retrospective cohort study from one academic tertiary centre. Adult and paediatric PCD patients with a confirmed diagnosis [5] were included. The analysis of the patients' hospital pathways was carried out based on an administrative database, the "Programme De Médicalisation des Systèmes d'Information" (PMSI), for the period 2010-2018. The collected data contains information such as date of admission, patient age, medical act codes using French common classification of medical acts (CCAM 14) or diagnosis (ICD-10). All personal data were either discarded or anonymised using one-way encryption prior to being transmitted and used for analysis. Data processing was carried out using Python version 3.7 and SQL. The study conforms to the Declaration of Helsinki and was approved by the institutional review board of the