Definitions of bronchopulmonary dysplasia do not influence quantitative lung ultrasound predictive accuracy

Introduction: Quantitative lung ultrasound (LUS) predicts bronchopulmonary dysplasia (BPD), but variability in BPD definitions raises concerns about its predictive consistency. We hypothesized that predictive accuracy of LUS would remain stable regardless of the definition applied. Methods: In this prospective, multicenter cohort study, preterm infants ≤30 weeks’ gestation underwent extended LUS (eLUS, adj-eLUS) aeration score at days 10, 21, and 28. BPD was assessed at 36 weeks postmenstrual age using Jobe & Bancalari (2001), NICHD (2018), and Jensen (2019) definitions. ROC analysis compared predictive performance (AUC) across definitions. Results: Among 337 infants (mean gestational age: 27 weeks, mean birthweight: 941 g), BPD incidence ranged from 22.8–25.8% depending on definition. AUCs for BPD prediction ranged between 0.732 and 0.832. The mean difference (ΔAUC) between definitions was minimal (≈0.02, 95%CI: 0.01–0.03) and non-significant at all timepoints. Conclusions: Quantitative LUS reliably predicts BPD regardless of its definition, and this support its use in early respiratory care and monitoring.