[Redefining the concept of elderly--for "successful aging" society].

For a long time, the term "elderly" has been defined as a chronological age of 65 years or more. However, in modern Japan where the average life span is 80 years or more, it has become already outdated to group the elderly into a chronological age of 65 years or more. We have attempted to review the definition of the elderly by analyzing data from statistics on population dynamics, trends of Japanese public opinion, long-term longitudinal epidemiological studies and clinical and pathological studies. We propose rebuilding a more flexible definition of the elderly based on comprehensive evidence in all aspects of social, cultural and medical sciences. In addition, our proposal might be a starting point in elaborating a strategy for a successful aging society.