Table 5.

Hierarchical regression models to predict symptom severity from gross motor DQ and fine motor DQ in 4-year-old group.

Group	Explanatory variables	Step 1	Step 2a	Step 2b
		β	β	β
ADHD group 1	Age	−0.10	−0.01	−0.05
	Gender	−0.51*	−0.50*	−0.56*
	Adaptive behavior DQ	−0.11	−0.34	−0.24
	Language DQ	0.11	0.22	0.07
	Personal-social DQ	0.04	0.06	0.06
	Gross motor DQ		0.46*
	Fine motor DQ			0.34
		R2 = 0.31	R2 = 0.48*	R2 = 0.40*
			ΔR2 = 0.17*	ΔR2 = 0.09
Group	Explanatory variables	Step 1	Step 2a	Step 2b
		β	β	β
Symptom-like group 1	Age	0.19	0.20	0.17
	Gender	−0.38*	−0.42*	−0.39*
	Adaptive behavior DQ	−0.07	−0.05	−0.08
	Language DQ	0.16	0.14	0.13
	Personal-social DQ	0.09	0.03	0.09
	Gross motor DQ		0.19
	Fine motor DQ			0.08
		R2 = 0.21*	R2 = 0.24*	R2 = 0.21*
			ΔR2 = 0.03	ΔR2 = 0.01

The alpha value is set to 0.05/4 ≈ 0.017.

^*p < 0.05, corrected with Bonferroni correction. The response variable is symptom severity (Impulsivity-hyperactivity + Hyperactivity index).