Anne Schlegtendal

Background PCD is a genetic disease leading to a decline in pulmonary function. There is only little knowledge of factors determining the long‐term pulmonary outcome. Especially adherence has not been addressed yet although being an independent risk factor for an increased loss of lung capacity in other chronic respiratory diseases. Objective Assessing the impact of bacterial airway colonization and adherence on long‐term lung function in patients with PCD. Methods Data on colonization and lung function parameters like forced expiratory volume in the first second (FEV 1, Z‐ score) and lung clearance index (LCI 2,5% ) were collected for 7.01 ± 2.2 years (893 quarters) in 44 PCD patients. Adherence was classified as good, moderate or poor. The impact of both adherence and colonization was assessed for the long‐term course of FEV1, the association of colonization with lung function also quarterly. Statistics Kruskall–Wallis test, T test, ANOVA, linear regression, linear mixed model. Results Chronic colonization did not show any impact on the for long‐term course of FEV 1 , but adherence was a significant factor: patients with good adherence showed better FEV 1 at the end of the observation period than children with poor adherence (–0.15 ± 0.88 vs. –2.63 ± 1.79, p < 0.01). Conclusion Adherence has not yet been investigated for PCD. However, we found it to be a major significant factor affecting long‐term FEV 1 in PCD. Thus, it should be taken into consideration in the treatment protocols for PCD.