A modified version of the BSID-II scales for cognitive matching of infants with and without Down syndrome

Background Many measures of infants’ early cognitive development, including the BSID-II, mix together test items that assess a number of different developmental domains including language, attention, motor functioning and social abilities, and some items contribute to the assessment of more than one domain. Consequently, the scales may lead to under- or over-estimates of cognitive abilities in some clinical samples and may not be the best measure to use for matching purposes. Method To address this issue we created a modified form of the BSID-II (the BSI-M) to provide a ‘purer’ assessment of the general cognitive capacities in infants with DS from 6 through to 18 months of age. We excluded a number of items that implicated language, motor, attentional and social functioning from the original measure. This modified form was administered to 17 infants with Down's syndrome when 6-, 12- and 18-months-old and to 41 typically developing infants at 4-, 7- and 10-months. Results The results suggested that the modified form continued to provide a meaningful and stable measure of cognitive functioning and revealed that DS infants may score marginally higher in terms of general cognitive abilities when using this modified form than they might when using the standard BSID-II scales. Conclusions This modified form may be useful for researchers who need a ‘purer’ measure with which to match infants with Down syndrome and other infants with IDs on cognitive functioning