International validation of the Bronchiectasis Health Questionnaire (BHQ): data from the EMBARC-BRIDGE study

<b>Introduction:</b> The Bronchiectasis Health Questionnaire (BHQ) is a short and simple disease-specific tool that measures quality of life in patients with bronchiectasis and has a total score. It was originally developed in English and international validation is required. <b>Methods:</b> Data was prospectively collected from the EMBARC-BRIDGE study. All participants completed the BHQ (10 items, total score) and a Quality of Life - Bronchiectasis (QoL-B) (37 items, 8 domain scores) questionnaire. Follow-up data at 12 months were used to assess test-retest reliability. <b>Results:</b> 433 patients were included from 9 countries. Cronbach α from the international data of the BHQ was 0.72 and the intraclass correlation coefficient (ICC) over 12 months was 0.67. Convergent validity showed good correlation with lung function (FEV1% predicted r=0.251; 95%CI 0.15 to 0.35), sputum volume (r=-0.277; 95%CI -0.37 to -0.18) and all QoL-B domains [from r=0.369 (treatment burden) to 0.794 (respiratory symptoms)]; all p&lt;0.0001. Patients with worse BHQ scores&nbsp;had more severe disease [mild (63.1, IQR 17.1) vs. moderate (61.6, IQR 16.0) vs. severe (56.1, IQR 13.8)], more annual exacerbations [no exacerbations (63.1, IQR 15.8) vs. 1-2&nbsp; exacerbations (60.1, IQR 13.1) vs. ≥3 exacerbations (56.1, IQR 13.7)] and more hospitalisations [≥1 hospitalisations (56, IQR 15.5) vs. no hospitalisations (62, IQR 16.0). All p-values &lt;0.001. <b>Conclusion:</b> BHQ shows good internal consistency, reliability, and convergent validity in an international bronchiectasis cohort of 8 languages.&nbsp;BHQ has a total score (10 items) that correlates&nbsp;highly with the QOL-B Respiratory Symptoms domain and significantly with clinical outcomes.