Table 2

Indicators of intellectual disability associated with congenital hypothyroidism among unscreened populations

Indicator of intellectual disability
ReferenceCountryNo testedBirth yearsAge at testing (years)MeasureMean IQPercentage with low IQIQ rangePercentage in special schools
Alm et al26Sweden391969–19717–9Wechsler Intelligence Scale for Children888% <7050–1138
16% <75
Alm et al27Sweden141977–19785Griffith's Developmental quotient8714% <7045–116Not reported
28% <80
Frost et al29England451965–19757–15Wechsler Intelligence Scale for Children—revised82NR40–11213
Hulse et al30England941957–19757 or olderWechsler Intelligence Scale for Children—revised8227% <70NR29
  • IQ, intelligence quotient; NR, not reported.