Personality traits as predictors of decline in higher-level functional capacity over a 7-year follow-up in older adults: the Ohasama study.
Numerous factors that affect functional decline have been identified, and personality traits are considered to be an important factor in functional decline risk. The Tokyo Metropolitan Institute of Gerontology Index of Competence (TMIG) was developed to measure three higher-level functional capacities, instrumental activities of daily living, intellectual activity, and social roles, in Japanese elderly, which were previously not assessed adequately with existing scales of functional decline. The objective of this study was to explore the effect of personality traits as predictors of higher-level functional decline over a 7-year follow-up in a rural Japanese community. Data on 676 participants (mean 67.1 years) who were free of functional decline and had completed questionnaires at baseline and 7 years later, were analyzed. Demographic characteristics, lifestyle and personality characteristics were obtained from a self-administered questionnaire at baseline. Higher-level functional decline was examined using the subscales of the TMIG at baseline and at a 7-year follow-up examination. Over the 7-year study period, 21.7% of eligible participants reported decline in higher-level functional capacity. After adjustment for putative confounding factors, the traits that were significant predictors of decline in higher-level functional capacity at the 7-year follow-up had higher psychoticism scores [odds ratio (95% confidence interval) 2.12 (1.23-3.66)] and lower extraversion scores [1.89 (1.01-3.56)]. The personality traits of higher psychoticism and lower extraversion were significantly associated with a risk of future functional decline. A better understanding of these personality traits may help identify of at-risk individuals and could help reduce functional decline in older adults.