Intellectual activity and likelihood of subsequently improving or maintaining instrumental activities of daily living functioning in community‐dwelling older Japanese: a longitudinal study

Abstract

To test the a priori hypothesis that increase or maintenance of the level of cognitive activity would be independently associated with a subsequent beneficial impact (i.e. improvement or maintenance) on instrumental activity of daily living (IADL) functioning. Observational study using 4-year longitudinal data from 1477 community-dwelling Japanese who were 66 years and older and living in Yoita town, a rural community located in the northwest along the Sea of Japan. Baseline assessment occurred in November 2000. Intellectual Activity and IADL were evaluated using the Tokyo Metropolitan Institute of Gerontology (TMIG) Index of Competence. Increase or maintenance of exposure to intellectual activities over a period of 2 years was associated with increased likelihood of better IADL functioning trajectory (i.e. improvement or stability) over the subsequent 2 years (OR: 1.63; 95% CI: 1.03-2.56; p = 0.035), even after adjustment for major confounders. This study documented a longitudinal, independent association of exposure to intellectual activities with better IADL functioning over time. These findings provide preliminary support for promotion of exposure to intellectual activities among older adults as an opportunity to prevent disability in the older segment of the population. Assessment of public health programs targeting such an opportunity is warranted.