TABLE 7.      COMPARISON OF MEANS (STANDARD DEVIATIONS)
FOR SELECTED DEMOGRAPHIC VARIABLES AND                             
WHO-NCTB TEST SCORES FOR FOUR COUNTRIES

TEST              SOUTH AFRICA       NETHERLANDS¹¹    SINGAPORE⁸   NICARAGUA⁹
                           n=228                                  n=46                   n=17                       n=25

Simple
Reaction            275.3(68.1)            241.6(30.1)                             -                       308(50)
Time

Santa Ana
Dominant            35.9(7.7)                 43.8(4.9)                  36.2(4.6)                    35.6(7.0)

Santa Ana
Non-dominant    32.5(7.0)                  42.7(4.6)                  35.8(4.8)                        -

Pursuit
Aiming                 79.9(36.6)             149.5(33.8)             188.8(28.8)                  94.4(29.9)
Correct

Digit
Symbol               20.9(9.5)                 53.8(10.9)                46.5(11.8)                  25.4(11.9)
Substitution

Digit span
Forward                5.2(1.0)                    5.4(1.8)                  *13.4(2.8)                     6.3(3.2)

Benton Visual     6.4(1.7)                     8.6(1.1)                     7.9(1.4)                      1.1(2.2)
Retention

Age                   46.0(9.0)                     36-45                      35.7(12.1)                   17.8(9.3)

Education (y)      6.1(3.5)                          -                            -                                   -


 

* Score is the sum of digit span forwards and backwards

Myers JE, Nell V, Colvin M, Thompson ML. Neuropsychological function in solvent exposed South African paintmakers. Journal of Occupational and Environmental Medicine 1999;41(11):1011-1018.