Study flowchart. Longitudinal data from 136 consecutive patients were included in the study. Ultimately, the dataset was split into two time series to enable additional analysis: a learning sample (first 69 patients), which was used to establish the best predictive model, and a test sample (last 67 patients), which has not been used during the previous phase and was used to test model generalization. COPD = severe chronic pulmonary obstructive pulmonary disease with forced expiratory volume less than 50%; NIV = noninvasive ventilation; PLS = partial least-square regression; PSV = pressure support ventilation.