Data on primary ciliary dyskinesia (PCD) epidemiology is scarce and published studies are
characterised by low numbers. In the framework of the European Union project BESTCILIA we aimed to
combine all available datasets in a retrospective international PCD cohort (iPCD Cohort).
We identified eligible datasets by performing a systematic review of published studies containing clinical
information on PCD, and by contacting members of past and current European Respiratory Society Task
Forces on PCD. We compared the contents of the datasets, clarified definitions and pooled them in a
standardised format.
As of April 2016 the iPCD Cohort includes data on 3013 patients from 18 countries. It includes data on
diagnostic evaluations, symptoms, lung function, growth and treatments. Longitudinal data are currently
available for 542 patients. The extent of clinical details per patient varies between centres. More than 50%
of patients have a definite PCD diagnosis based on recent guidelines. Children aged 10–19 years are the
largest age group, followed by younger children (⩽9 years) and young adults (20–29 years).
This is the largest observational PCD dataset available to date. It will allow us to answer pertinent
questions on clinical phenotype, disease severity, prognosis and effect of treatments, and to investigate
genotype–phenotype correlations.