Subjective usefulness and 6-year mortality risks among elderly persons in Japan.

Several studies have demonstrated that the loss of a sense of one's own self-worth has an influence on the health status, psychological functioning, and quality of life in the aged. We used longitudinal data from 784 elderly residents (mean age = 73 years) to examine the relationship between subjective usefulness and 6-year mortality. We hypothesized that subjective usefulness is an important indicator of quality of life among the elderly population, and subsequently of mortality. We elicited information on subjective usefulness at baseline by using a self-administered questionnaire. Results of longitudinal analyses showed that subjective usefulness may be significantly associated with self-rated health and subsequent mortality. This indicates that subjective usefulness plays an important role in enhancing survival in the elderly population.