Considerations for the use of the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) in cross-country comparisons of cognitive aging and dementia.

Associations between IQCODE and cognitive testing were similar in the United States and England but differed in India. In India, the IQCODE may be less sensitive to impairments among those with low cognition and no education. Informant characteristics may differentially impact informant reports of decline across countries. Adjustments or culturally sensitive adaptations may improve cross-national comparability.