Sensitivity and feasibility of lung ultrasound in bronchiolitis—reply to the correspondence letter by Catalano

Excerpt

We thank Dr Catalano et al. for their interest on our article. The comment raises two important issues, one regarding the test sensitivity and the second, more general, on test feasibility. Assuming the final diagnosis as a gold standard, lung ultrasound (LUS) showed an excellent sensitivity (47/52 vs 38/52 of chest x-ray, 90 vs 73 %), but we have to consider the observational characteristics of the study design, performed in a real-world setting with real patients, real problems, and real doctors, with clinically driven indication to chest x- rays. This is typical of an observational effectiveness study; it is not an efficacy study, evaluating the technique under ideal conditions, and the observed results can be more directly relevant to clinical practice but also vulnerable to selection bias [1]. …