Relationship between instrumental activities of daily living performance and incidence of mild cognitive impairment among older adults: A 48-month follow-up study

Early prevention of mild cognitive impairment MCI is crucial because individuals with MCI are at high risk for progression to dementia. The purpose of the present study was to examine the relationship between the performance of instrumental activities of daily living IADL and future incidence of MCI among community-dwelling older adults in Japan. A total of 1595 individuals without cognitive impairment at baseline participated in this prospective cohort study with a 48-month follow-up period. Performance on the following IADL was assessed at baseline: handling cash and banking, shopping for necessities, going out using buses/trains, using maps to travel to unfamiliar places, and operating video/DVD players. Objective cognitive screening using the National Center for Geriatrics and Gerontology-Functional Assessment Tool and Mini-Mental State Examination was conducted at baseline and follow-up; new MCI incidence over the 48 months was determined. Of all participants, 922 (57.8 %) had a limitation in at least one IADL at baseline. During the follow-up period, 179 (11.2 %) participants experienced a transition from normal cognition to MCI. Participants who had not engaged in "going out using buses/trains" or "using maps to travel to unfamiliar places" at baseline showed a significantly higher risk of MCI incidence than those who had engaged in such activities. Limitations in outdoor IADL were associated with MCI onset. Individuals with such limitations need to be monitored, as these limitations are strong indicators of cognitive decline and MCI.