Figure 2.

Examples of FIDDLE input and output for time-invariant and time-dependent data. In this example, each ID represents a patient (an example). Timestamps are recorded in hours. Only the subset of input/output relevant for illustration is shown. The bins for numerical variables and the categories for categorical variables are automatically determined from the entire input data table (not shown). (A) Time-invariant input data and output features for Patient 1. Patient 1 is female with an age of 55. The feature “sex = female” is dropped in the post-filter step because it is perfectly correlated with “sex = male.” (B) Time-dependent input data and output features for Patient 2. At t = 1.5 h, Patient 2 had an insulin administration of 3 units via drug push. No imputation in 2–4 h is done, since the 3 variables related to insulin are not considered “frequent,” resulting in 0 s in the output features for the corresponding time bins. FIDDLE: Flexible Data-Driven Pipeline; ID: unique identifier; IV: intravenous.