Impaired instrumental activities of daily living affect conversion from mild cognitive impairment to dementia: the Osaki-Tajiri Project

Abstract

Aim: To determine whether impaired instrumental activities of daily living affect conversion from mild cognitive impairment to dementia for subjects in a community.

Methods: This is a 7-year retrospective study that followed 226 randomly selected participants from the Prevalence Study 1998 in Tajiri in northern Japan who had Clinical Dementia Rating 0.5. Instrumental activities of daily living levels were assessed with a 21-item questionnaire. We analyzed the scores at baseline between the converters to dementia and non-converters.

Results: The converters had lower baseline scores on the 'bed making' and 'mode of transportation' items compared with the non-converters; the former item was significant after a stepwise logistic regression analysis that excluded age and Mini-Mental State Examination effects. In gender analysis, female converters had lower baseline scores on the 'bed making' and 'cleaning' items. For male participants, no items were found to have such an effect.

Conclusions: We suggest that when individuals with mild cognitive impairment are limited in their performance of instrumental activities of daily living, this is predictive of dementia onset.