Background: Pulmonary exacerbations cause significant morbidity in patients with primary ciliary dyskinesia (PCD) and their frequency can be used as a primary outcome in prospective clinical trials. Two definitions (Def) of pulmonary exacerbations in PCD have been published recently: Def-1, based on a consensus agreement¹; Def-2, based on antibiotics use^2,3. To date little is known on the burden of pulmonary exacerbations in PCD patients.

Aim: We aimed to record the exacerbation rate within one year based on the above definitions, as well as based on self-reported assessments. Furthermore, we aimed to assess the agreement between the two definitions, and their correlation with the self-reported exacerbation rate.

Methods: Data were prospectively collected in monthly telephone interviews via a structured questionnaire.

Results: In total 358 patients (45.8% females) from 11 centers, median age 17.5 years (range 0-72), with confirmed diagnosis of PCD participated in the study. Within 12 months, 80.2% of patients had at least one exacerbation per year, as defined by Def-1 or Def-2 (Table 1). Self-reported exacerbations rate is significantly higher compared to Def-1 and Def-2 (Wilcoxon test, p<0.0001). Between Def-1 and Def-2 there is a moderate agreement (Cohen?s kappa=0.59). 

Conclusion: This is the first study that provides prospective evidence on the burden of pulmonary exacerbations in patients with PCD.

Table 1: Exacerbations rate within one year

*Friedman test, p<0.0001

¹Lucas, et al. ERJ Open Res 2019

²Kobbernagel, et al. BMC Pulm Med 2016

³Ratjen, et al. Eur Respir J 2016