Table 3.

Model Performance for Brain Age Prediction

	Non-IHD (Train)	Non-IHD (Test)	IHD
MAE, y	4.72	4.69	6.96
R2 (variance in age explained)	0.38	0.39	−0.76

MAE indicates the mean difference between the chronological age and the predicted brain age expressed in years, with higher values indicating older-appearing brain. R² represents the proportion of variance in the predicted brain age explained by the used features in the model. In IHD group, a greater deviation of predicted brain age from chronological age was observed compared to non-IHD (test-set) (MAE = 6.96 years for IHD vs MAE = 4.69 years for non-IHD).

MAE = mean absolute error; R² = coefficient of determination; other abbreviation as in Table 1.