[A study of associations between daily-social activity of elderly people living at home and symptoms of forgetfulness. Screening for dementia risk].

PURPOSE: Functional decrease in brain activity as a factor inducing dementia is due not only to aging but also to decrease in social exchange, loss of something to live for, and decrease in physical activity with indoor confinement. It might therefore be possible to use these parameters to screen for risk of dementia in community care programs. In the present study we evaluated the association between decreased daily-social activity and symptoms of forgetfulness. METHODS: The subjects were 6,486 people aged > or = 65 years living in 3 municipalities in Yamanashi Prefecture. A survey table concerning daily-social activity and symptoms of forgetfulness was produced, and a whole-sample survey was performed by mail. Cluster analysis of items such as symptoms of forgetfulness was performed, and clusters were obtained. Associations between these clusters and daily-social activity were then analyzed by the Mann-Whitney test. RESULTS: Of 5,556 replies (recovery rate, 85.7%), 3,067 with all items filled out (effective reply rate, 55.2%) were analyzed. None of the 21 items for forgetfulness was applicable in 600 of the subjects (19.6%). Cluster analysis of the other 2,467 subjects with 1 or more symptoms revealed the following 5 clusters: "common forgetfulness symptoms" consisting of 2 items, "decreased will to live" consisting of 8 items, "amnesic symptoms" consisting of 4 items, "emotional responses" consisting of 2 items, and "difficulty in daily life" consisting of 5 items. There were 31 types of cluster combinations in the subjects, and the most frequently applicable cluster was "common forgetfulness symptoms" (658 subjects, 21.5%). Comparison of the daily-social activity between the cluster groups showed significant differences in many of the items for daily-social activity with reference to the "decreased will to live". CONCLUSION: Among forgetfulness symptoms, items classified as related to "decreased will to live" were most associated with daily-social activity. This suggests utility for evaluation of daily-social activity, including intellectual and social activity frequency in elderly people in communities to select people for care programs for prevention of secondary dementia.