The Swiss Primary Ciliary Dyskinesia registry: objectives, methods and first results

Abstract

Primary ciliary dyskinesia (PCD) is a rare, hereditary, multiorgan disease caused by defects in the structure and function of motile cilia. It results in a wide range of clinical manifestations, most commonly in the upper and lower airways. Central data collection in national and international registries is essential to studying the epidemiology of rare diseases and filling in gaps in knowledge of diseases such as PCD. For this reason, the Swiss Primary Ciliary Dyskinesia Registry (CH-PCD) was founded in 2013 as a collaborative project between epidemiologists and adult and paediatric pulmonologists. We describe the objectives and methodology of the CH-PCD, present initial results, and give an overview of current and ongoing projects. The registry records patients of any age, suffering from PCD, who are treated and resident in Switzerland. It collects information from patients identified through physicians, diagnostic facilities and patient organisations. The registry dataset contains data on diagnostic evaluations, lung function, microbiology and imaging, symptoms, treatments and hospitalisations. By May 2018, CH-PCD has contacted 566 physicians of different specialties and identified 134 patients with PCD. At present, this number represents an overall 1 in 63,000 prevalence of people diagnosed with PCD in Switzerland. Prevalence differs by age and region; it is highest in children and adults younger than 30 years, and in Espace Mittelland. The median age of patients in the registry is 25 years (range 5–73), and 41 patients have a definite PCD diagnosis based on recent international guidelines. Data from CH-PCD are contributed to international collaborative studies and the registry facilitates patient identification for nested studies. CH-PCD has proven to be a valuable research tool that already has highlighted weaknesses in PCD clinical practice in Switzerland. Trial registration number NCT03606200

Estimates of primary ciliary dyskinesia prevalence: a scoping review

“…After deduplication, there were 3484 unique abstracts that were reviewed and 34 were identified for full text review. Of those, 8 met the inclusion and exclusion criteria and were included in the scoping review [Figure 1] [5,15,[22][23][24][25][26][27].…”

Respiratory symptoms of Swiss people with Primary Ciliary Dyskinesia

“…Another strength was the representative study population and the high response rate. Since the study was nested in the national CH-PCD registry, it allowed for an unselected population of people with PCD, including children and adults [19].…”

“…Our study was a cross-sectional questionnaire survey nested in the Swiss PCD registry (CH-PCD) [19]. CH-PCD is a patient registry (www.clinicaltrials.gov, identifier NCT03606200) that collects demographic characteristics, diagnostic test results, clinical data and information about management of patients in Switzerland.…”

Physical activity, respiratory physiotherapy practices, and nutrition among people with primary ciliary dyskinesia in Switzerland – a cross-sectional survey

“…Our national cross-sectional questionnaire survey was nested in the Swiss PCD registry (CH-PCD). CH-PCD is a population-based patient registry (www.clinicaltrials.gov; identifier NCT03606200) enrolling all people with confirmed or clinical diagnoses of primary ciliary dyskinesia in Switzerland [19]. Patients with a clinical primary ciliary dyskinesia diagnosis have a strong clinical suspicion, such as situs anomalies, persistent cough, persistent rhinitis, chronic or recurrent upper or lower respiratory infections and history of neonatal respiratory symptoms as term infants, but have not completed the diagnostic algorithm and have negative or ambiguous results for the tests performed so far [19][20][21].…”

“…Our study has several limitations. Although we invited all people enrolled in CH-PCD, selection bias is possible because primary ciliary dyskinesia in Switzerland is underdiagnosed [19]. The COVID-19 pandemic could have affected physical activity.…”