Fig 4. Performance assessment of BiLSTM classifiers on internal and external testing sets.

A-D. ROC curves displaying performance metrics on an expert-labelled internal testing set (n = 329 Normal, n = 601 Abnormal, n = 35 Uncertain). E-H. ROC curves demonstrating classifier performance on the external MIMIC-CXR expert-labelled free-text reports (n = 272 Normal, n = 184 Abnormal, n = 9 Uncertain).