Table 2 Selected demographic characteristics, and Wechsler IQ by study groups

n (749)

411

202

73

63

Male: n (%)

209 (50.9)^a

178 (88.1)^b

63 (86.3)^b

42 (66.7)^a

99.021

<0.001

Age range

4–14

4–14

6–12

4–12

Age (years): mean ± SD

7.43 ± 2.08^a

6.37 ± 2.35^b

8.41 ± 1.65^c

7.66 ± 2.06^a

20.611

<0.001

VIQ: mean ± SD

-

83.60 ± 28.05 ^a

98.65 ± 15.77 ^b

59.96 ± 15.09 ^c

52.064

<0.001

PIQ: mean ± SD

-

84.88 ± 23.83 ^a

92.72 ± 14.56 ^b

64.96 ± 14.15 ^c

37.044

<0.001

FIQ: mean ± SD

-

82.66 ± 26.65 ^a

95.43 ± 14.57 ^b

58.36 ± 14.79 ^c

53.834

<0.001