Figure 1.

Overview of study methodology. A, An illustration of the study design describing the use of machine learning to predict the outcome (defined as surgery ending by 5 pm and patient discharged from recovery room by 7 pm). Each model was based on whether the start time of the surgery was 1 pm, 2 pm, 3 pm, or 4 pm. B, Data pipeline. OR indicates operating room; PACU, postanesthesia care unit; ROC, receiver operating characteristic; SMOTE, synthetic minority oversampling technique.