PREVALENCE OF AGING-ASSOCIATED COGNITIVE DECLINE IN AN ELDERLY POPULATION

Different diagnostic definitions have been proposed for use in the cha racterization of mild cognitive disorders associated with ageing. Prev iously, we reported a high (38.4%) prevalence of age-associated memory impairment (AAMI) using the National Institute of Mental Health crite ria in an elderly population. Recently, a work group of the Internatio nal Psychogeriatric Association proposed criteria for 'ageing-associat ed cognitive decline' (AACD). The objective of this study was to evalu ate the prevalence of AACD in an elderly population. We examined 403 r andomly selected subjects (68-78 years of age) with tests of memory, c ognitive processing, attention, verbal and visuoconstructive functions and with a structured questionnaire for health status and subjective complaints of cognitive decline. In all, 26.6% of the subjects (24.4% of women, 30.1% of men) fulfilled the AACD criteria. The prevalence wa s slightly related to age and education. The rate was lowest in the ol dest age group of 75-78 years (20.5%) and highest in the age group of 71-74 years (30.5%). Subjects with less than 4 years of education had the lowest (14.3%) and subjects with more than 6 years of education ha d the highest rate (29.4%) for AACD. However, the differences between these subgroups were not statistically significant. These results sugg est that the prevalence of AACD is lon er than that of AAMI. As AAMI t ends to identify a very heterogeneous subject group, the AACD diagnosi s, which takes into account age and education specific norms in its in clusion criteria, might prove superior to AAMI in differentiating a me aningful subgroup from an elderly population both for research purpose s and in clinical settings.