RATIONALE:

Testing for underlying etiology is a key part of bronchiectasis management, but it is unclear whether the same extent of testing is required across the spectrum of disease severity.

OBJECTIVES:

The aim of the study was to identify the etiology of bronchiectasis across European cohorts and according to different levels of disease severity.

METHODS:

This was an analysis of seven databases of adult outpatients with bronchiectasis prospectively enrolled at the bronchiectasis clinics of university teaching hospitals in Monza (Italy), Dundee and Newcastle (UK), Leuven (Belgium), Barcelona (Spain), Athens (Greece) and Galway (Ireland). All the patients underwent the same comprehensive diagnostic work-up as suggested by the British Thoracic Society in every site.

MEASUREMENTS AND MAIN RESULTS:

Among the 1,258 patients enrolled, an etiology of bronchiectasis was determined in 60%, including post-infective (20%), COPD-related (15%), connective tissue disease-related (10%), immunodeficiency (5.8%) and asthma-related (3.3%). An etiology leading to a change in patient's management was identified in 13% of the cases. No significant differences in etiology of bronchiectasis were present across different levels of disease severity, with the exception of a higher prevalence of COPD-related (p<0.001) and a lower prevalence of idiopathic bronchiectasis (p=0.029) in severe patients.

CONCLUSIONS:

Physicians should not be guided by disease severity in suspecting specific etiologies in patients with bronchiectasis, although idiopathic bronchiectasis appears to be less common in the most severe patients.