METHODS: Children undergoing FB were prospectively enrolled. Their FB was digitally recorded and assessed (two clinicians blinded to each other and clinical history) for six features: secretion amount (six-point scale), secretion color (BronkoTest, 0-8), mucosal oedema (0-3), ridging (0-3), erythema (0-3), and pallor (0-3) based on pre-determined criteria. We correlated (Spearman's rho) each feature with bronchoalveolar lavage (BAL) neutrophil percentage (neutrophil%). BScore was then derived using models with combinations of the six features that best related to airway BAL neutrophil%. The various models of BScore were plotted against BAL neutrophil% using receiver operating characteristic (ROC) curves.

RESULTS: We analyzed 142 out of 150 children enrolled. Eight children were excluded for unavailability of BAL cytology or FB recordings. Chronic/recurrent cough was the commonest indication for FB (75%). The median age was 3 years (IQR, 1.5-5.3 years). Secretion amount (r = 0.42) and color (r = 0.46), mucosal oedema (r = 0.42), and erythema (r = 0.30) significantly correlated with BAL neutrophil%, P 10%).