Background: The FOLLOW-PCD questionnaire for patients with primary ciliary dyskinesia (PCD) is part of the FOLLOW-PCD standardised form, developed within the framework of BEAT-PCD.  It collects information on symptoms and lifestyle and is available in 3 age-adapted versions: adults, adolescents and parents of children <14 years old. We piloted the questionnaire in a large collaborative cohort study.

Methods: Participants of the ear?nose?throat prospective international cohort of patients with PCD (EPIC-PCD) completed the paper version of the questionnaire at clinical follow-up. We assessed completeness of data and studied factors associated with it.

Results: 422 participants (47% females) completed the questionnaire; 148 adults, 85 adolescents and 189 parents of children. For most questions on symptom frequency, completeness was ?95%; least complete were snoring (87%), chest pain (92%) and hearing problems (93%). Most questions on symptom characteristics, e.g. mucus colour, were ?90% complete. Questions related to situations triggering symptoms were least complete with 83% completeness for nasal symptoms, and 88% for headaches. Only 76% of adults completed the modified Medical Research Council dyspnea scale. Among lifestyle, questions on smoking were most complete (>95%) and questions related to occupation least (85-90%). Sex was not associated with completeness; adults provided least missing answers.

Conclusion: The FOLLOW-PCD questionnaire showed good completeness, especially for symptoms. We will use these results together with the ongoing cognitive validation to refine the questionnaire to a final version.

Funding: SNF PZ00P3_185923