Poster: Rasch Analysis to Test the Cross-Cultural Item Equivalence of the Alzheimer’s Disease Assessment Scale – Cognitive (ADAS-Cog)
Introduction: Bias is a significant challenge to the validity of cognitive tests. Differential item functioning (DIF) is present when different groups have differing responses on test items, after controlling for overall ability.Differential Item Functioning (DIF) investigates the items in a test, one at a time, for signs of interactions with sample characteristics. Item functioning is intended to be invariant with respect to aspects of the participants, such as gender, ethnicity and cultural status. The DIF analysis for one item is as independent as possible of the DIF analyses of the other items. But a consequence is that the overall impact of item DIF, accumulated cross the whole test, is unclear.
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