Table 5

Mathematics test and laterality, stratified by right-hand motor score

	Test score	Unadjusted		Adjusted^*
	Mean value (SD)	Coefficient (95% CI)	p Value	Coefficient (95% CI)	p Value
Lowest third^† (right hand)
Laterality
Right	16.35 (10.28)	Reference		Reference
Left	15.42 (10.33)	−0.93 (−1.95 to 0.08)	0.071	−1.12 (−2.07 to −0.17)	0.021
Mixed	14.96 (10.29)	−1.39 (−2.67 to −0.11)	0.034	−1.33 (−2.53 to −0.13)	0.030
Left-hand motor score
Lowest third^†	15.57 (10.30)	−1.56 (−3.00 to −0.12)	0.034	−1.26 (−2.62 to 0.09)	0.067
Middle third	17.17 (10.35)	0.05 (−1.46 to 1.56)	0.951	0.15 (−1.27 to 1.57)	0.834
Highest third	17.13 (9.50)	Reference		Reference
Middle third (right hand)
Laterality
Right	17.47 (10.14)	Reference		Reference
Left	17.01 (10.54)	−0.46 (−1.61 to 0.70)	0.440	−0.22 (−1.32 to 0.89)	0.699
Mixed	16.63 (10.18)	−0.84 (−2.19 to 0.52)	0.226	−0.60 (−1.88 to 0.68)	0.360
Left-hand motor score
Lowest third^†	16.62 (9.86)	−1.06 (−2.03 to −0.09)	0.033	−0.77 (−1.69 to 0.15)	0.102
Middle third	17.63 (10.24)	−0.05 (−0.91 to 0.81)	0.912	0.14 (−0.68 to 0.96)	0.743
Highest third	17.68 (10.38)	Reference		Reference
Highest third (right hand)
Laterality
Right	18.36 (10.28)	Reference		Reference
Left	17.79 (9.94)	−0.57 (−1.78 to 0.63)	0.352	−0.77 (−1.91 to 0.36)	0.180
Mixed	17.65 (10.29)	−0.71 (−2.09 to 0.66)	0.310	−0.61 (−1.90 to 0.68)	0.352
Left-hand motor score
Lowest third^†	16.64 (10.51)	−1.93 (−3.47 to −0.39)	0.014	−1.73 (−3.27 to −0.40)	0.012
Middle third	17.84 (10.10)	−0.73 (−1.49 to 0.03)	0.060	−0.45 (−1.16 to 0.27)	0.221
Highest third	18.57 (10.28)	Reference		Reference

↵* Adjusted for laterality, left-hand motor score, sex and parental social class.
↵† The lowest third of the motor function tests indicates poorest performance (longest time to pick up 20 matches).