Multidimensional severity assessment in bronchiectasis:An analysis of 7 European cohorts.

Introduction: Bronchiectasis is a multidimensional disease associated with substantial morbidity and mortality. Two disease-specific clinical prediction tools have been developed, the Bronchiectasis Severity Index (BSI) and the FACED score, both of which stratify patients into severity risk categories to predict the probability of mortality.Methods: We aimed to compare the predictive utility of BSI and FACED in assessing clincially relevant disease outcomes across 7 European cohorts independent of their original validation studies.Results: The combined cohorts totalled 1,612. Pooled analysis showed that both scores had a good discriminatory predictive value for mortality (pooled AUC 0.76, 95% CI 0.74-0.78 for both scores) with the BSI demonstrating a higher sensitivity (65% versus 28%) but lower specificity (70% versus 93%) compared with the FACED score. Calibration analysis suggested that the BSI performed consistently well across all cohorts, while FACED consistently overestimated mortality in “severe” patients (pooled OR 0.33 (0.23, 0.48), p<0.0001). The BSI accurately predicted hospitalisations (pooled AUC 0.82, 95% CI 0.78-0.84), exacerbations, quality of life (QoL) and respiratory symptoms across all risk categories. FACED had poor discrimination for hospital admissions (pooled AUC 0.65, 95% CI 0.63-0.67) with low sensitivity at 16% and did not consistently predict future risk of exacerbations, QoL or respiratory symptoms. No association was observed with FACED and 6 minute walk distance (6MWD) or lung function decline.Conclusion: The BSI accurately predicts mortality, hospital admissions, exacerbations, QoL, respiratory symptoms, 6MWD and lung function decline in bronchiectasis, providing a clinically relevant evaluation of disease severity.