Table 1 Characteristics of the included studies

Ohmann 2009 [15]

Austria

36/34

14.03±2.55/

15.56±1.93

6.91±0.54/

9.29±0.40

4.39±3.10/

7.49±3.16 years

WISC-III, WAIS-R

cross-sectional

Zihl 2010 [23]

Germany

16/12

34.20±10.30/

30.50±12.80

6.80±0.50/

9.40±1.90

164.20±101.40/

197.80±146.80 months

DST, WMS-R

cross-sectional

Kaufmann 2012 [26]

Austria

15/15

14.70±4.10/

13.90±3.90

7.40±0.50/

9.20±1.20

6.80±4.50/

4.40±3.10 years

WISC-III, WAIS-R, SWM

cross-sectional

Abo-el-Asrar 2016 [24]

Egypt

17/33

11.18±1.85/

12.06±1.97

6.63±0.21/

9.35±1.69

5.47±1.55/

6.91±2.11 years

BVRT, WISC

cross-sectional

HE 2018 [25]

China

32/73

13.20±3.35/

11.85±3.37

6.60±0.69/

9.70±1.93

3.11±2.96/

2.30±2.78 years

WISC-RC, WAIS-RC

cross-sectional

STANISŁAWSKA-KUBIAK 2018 [18]

Poland

21/47

11.39±2.66/

13.35±2.31

-

4.50±2.99/

5.80±2.96 years

WISC-RC, Brickenkamp’s and Zillmer’s d2 test, The trial of 10 words

cross-sectional