Table 2.

Dataset changes due to chart review and data preprocessing

Process		Variables (+Target Classes)	Patients (N)
First CRC Dataset		142 (+ 1)	1511
Chart Review	1) Check extraction method and location	142 (+ 1)	1508
	2) Check for inappropriate data	142 (+ 1)	1496
	3) Select priority variables (First Processed CRC Dataset)	40 (+ 1)	1496
Data Preprocessing	1) Drop redundant variables	37 (+ 1)	1496
	2) Drop variables including 90% ↑ missing values	32 (+ 1)	1496
	3) Drop instances containing missing values	32 (+ 1)	1169
	4) One-hot encoding (Final CRC Dataset)	54 (+ 5)	1169
Data Split	1) Data split (training/testing)	54 (+ 5)	935 / 234