Assessment of cognitive decline in the elderly by informant interview.

Cognitive decline in a sample of 64 elderly people was assessed by a standardised informant interview dealing with changes in memory and intelligence which had taken place in the previous 10 years. Scores from the interview were found to correlate (r = 0.74) with the Mini-Mental State Examination. Moreover, the informant interview was found to be less affected by pre-morbid ability than the MMSE. Direct assessment of decline by informants may be a solution to the problem of contamination by pre-morbid ability which affects traditional cognitive screening instruments.