Quality of Life (QOL) Assessment for Japanese Elderly: the course of QOL studies and assessments of health-related and subjective QOL

Abstract

The aims of this review are to (1) outline the course of quality of life (QOL) studies in Japan, (2) clarify the concept and scale of health-related QOL and subjective QOL, (3) clarify the problems in the Japanese version of subjective QOL scales and the characteristics of subjective QOL in Japanese elderly, and (4) propose a direction of QOL assessment for the aging society in Japan. Since the 1970s in Japan, QOL has been studied in several fields, such as medical science, social psychology and gerontology, but a unified concept or definition of QOL has not been established. Health-related QOL, developed in the field of medical science, evaluates the individual condition from multiple dimensions including physical, psychological, social, functional and spiritual aspects. Since the aging society in Japan is largely composed of healthy elderly, comprehensive health-related QOL scales, which can provide continuous assessment from the disabled to healthy elderly, have a high degree of availability. Subjective QOL scales measure individual subjective evaluations of all aspects of daily life. Subjective QOL has mainly been assessed from the viewpoint of life satisfaction or morale. However, it has been reported that the existing scales have certain problems, and that subjective QOL is influenced by culture and individual values. In the aging society of Japan, it will be important to evaluate QOL in the elderly from the aspects of both health-related and subjective QOL to clarify the criteria for "successful aging". In addition, ikigai ("something to live for"), which is unique to Japan, will be an effective measure for evaluation of QOL.