Abstract
This study aimed to assess interrater agreement in lung ultrasound scores (LUS) among neonatologists with varying experience levels and an expert sonographer. A post hoc analysis was conducted on data from a prospective multicenter study involving 155 infants born <34 weeks' gestation, all with respiratory distress syndrome. A total of 629 lung scans were performed and video-recorded by 21 point-of-care sonographers, including both experienced (n = 7) and inexperienced (n = 14) evaluators. Subsequently, a blinded expert sonographer re-evaluated the assigned LUS values. The Cohen's kappa statistic for individual pulmonary field assessments ranged from 0.89 to 0.93, indicating nearly perfect agreement. The interclass correlation coefficient (ICC) confirmed excellent reliability on total LUS values, demonstrating similar performance of experienced (ICC = 0.92, 95% CI 0.90-0.94) and inexperienced sonographers (ICC = 0.93, 95% CI 0.92-0.94). This study underscores that lung ultrasound is easily learned, and LUS exhibits outstanding reproducibility, irrespective of the sonographer's level of experience.