Construction and validation of a machine learning algorithm-based predictive model for difficult colonoscopy insertion

Table 4 Performance of the three models

Evaluation indicator	Logistic		Least absolute shrinkage and selection operator		Random forest
	Training set	Validation set	Training set	Validation set	Training set	Validation set
Cut-off value	0.199	0.191	0.257	0.261	0.401	0.156
Sensitivity	0.826	0.925	0.924	0.868	1.000	0.981
Specificity	0.602	0.511	0.510	0.562	0.977	0.526
Accuracy	0.663	0.606	0.624	0.632	0.998	0.628
Youden index	0.428	0.436	0.434	0.430	0.977	0.507
F1 score	0.574	0.519	0.574	0.520	0.996	0.547
Area under the receiver operating characteristic curve	0.780 (0.737-0.823)	0.726 (0.654-0.799)	0.754 (0.710-0.798)	0.723 (0.656-0.791)	1.000 (1.000-1.000)	0.754 (0.688-0.820)
Brier score	0.165	0.168	0.190	0.174	0.024	0.160