Statistical Analysis
Data were tested for normality using the Kolmogorov-Smirnov test and expressed as the mean (standard deviation) or median (interquartile range), as appropriate. Receiver operating characteristic (ROC) analysis was used to evaluate the accuracy of the LUS to predict all kinds of respiratory support needs (comprehensively and separately). Areas under the curves (AUCs) and cutoff values showing the highest sensitivity were reported. The AUCs were compared using the method by Hanley and McNeil26, and p< .05 was considered statistically significant. Analyses were performed using SPSS version 15.0 (SPSS Inc.) and MedCalc version 13.3 (MedCalc bvba) statistical software.