Table 6.

Results of 1000 bootstrap resamples for each regression tree. For first level, the number in the box is the percentage of bootstrap samples in which the variable is chosen to be in the first level of the tree. For the second level, the number in the box is the percentage of bootstrap samples in which the variable is chosen to be in the second level of the tree.

	Executive Function (n=168)		General Memory (n=170)		Processing Speed (n=158)
Variable	First level (%)	Second level (%)	First level (%)	Second level (%)	First level (%)	Second level (%)
Right hemisphere sulcal similarity	0.4**	13.4	0.4	3.4	0.7**	9.6
d-TGA (vs. non-d-TGA)	0	0.3	0	0.2	7.1	3.4
ToF (vs. non-ToF)	0	0.1	0	0.9	0	0
Gestational age	1.3**	7.3	1.1	2.5	0.2	1.9
Self-reported white race	0.1	0.2	0	0	0	0
Family social class	2.9*	26.1	28.5*	37.5	0.5*	8.7
Genetic diagnosis	0	0	0	0	0	0
Age at first operation	0	5.8	0.8	7.5	0	2.8
DHCA duration	77.8*	18.1	49.1*	19.9	22.0**	19.2
Total support time	0.2	1.7	0.9**	3.1	0	3.8
Number of perioperative complications	0.1	1.6	1.5	2.9	0	0.4
Any neurological event	1	2.6	14.5**	15.6	0	3.2
Number of catheterizations	13.3**	16.7	2.9	3.8	18.9	10.5
Number of operations	2.8	3.5	0.3	0.3	45.0*	7.7
Age at MRI	0.1	2.6	0**	2.4	5.6*	28.8

^*Included in first or second level of presented regression tree (Figures 3–6).

^**Included in third level or lower of presented regression tree (Figures 3–6).

DHCA: deep hypothermic circulatory arrest, d-TGA: d-transposition of the great arteries, MRI: magnetic resonance imaging, ToF: Tetralogy of Fallot