The Fluidity of Health: Changes in Functional Abilities among Older Japanese

Anna Penner, University of California, Irvine
Yasuhiko Saito, Nihon University

We utilize the Nihon University Japanese Longitudinal Study of Aging data to examine the change in functional ability of Japanese 65 years or older over the span of 10 years. We use three scales (activities of daily living, instrumental activities of daily living, and activities necessary to operate outside the home) to investigate if some functions decline earlier or more quickly than others. While health among older adults is often thought to steadily decline, we find that there various rates of deterioration. We also find that functional improvement may occur simultaneously with functional deterioration, so that an individual who has one function diminish may see improvement in another function. The number of other functioning difficulties is the only consistent indicator besides age of the likelihood of a function improving or declining over time, though some functions are affected by other covariates such as gender or the presence of chronic illnesses.