{'fraction_non_alphanumeric': 0.02090747330960854, 'fraction_numerical': 0.016459074733096084, 'mean_word_length': 5.229916897506925, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
An Introduction of the Tokyo Metropolitan Institute of Gerontology Longitudinal Interdisciplinary Study on Aging (TMIG‐LISA, 1991–2001)

The 20th century was the era in which human beings started to experience genuine longevity. Especially in industrialized countries, the trend of low birth rate and low death rate has continued to progresses. As a result, the elderly population increases and the average life expectancy has lengthened remarkably., Japan has the longest life expectancy in the world. The rate of aging of the Japanese population is unprecedented in any other industrialized country. It took only 24 years for Japan to double its population of age 65 and above, from 7% in 1970 to 14% in 1994. Compared with 69 years taken in the US, 46 years in the UK, and 82 years in Sweden, the aging of the population in Japan has proceeded at an extremely high speed. What is alarming is that judging from the Japanese experience, other nations are also likely to be confronted with an aging society within a short span of time. It is now generally accepted that longitudinal studies are essential for the study of the aging process. Longitudinal study designs differ from cross-sectional research designs in that they allow serial measurements on a single group of individuals, thereby permitting the researcher to assess the rates of change in selected measures over time. Surprisingly, there are few multidisciplinary longitudinal studies on aging using large, nationally representative samples. The Tokyo Metropolitan Institute of Gerontology Longitudinal Interdisciplinary Study on Aging (TMIG-LISA) was designed to meet the need for a major interdisciplinary longitudinal study on aging that employs a large, nationally representative sample. The TMIG-LISA consists of three major disciplines: medical, psychological, and social sciences. The project team is composed of researchers inside and outside the Institute. Study areas vary according to the discipline. Observational and analytical studies have been planned to continue for more than 10 years. In addition, since 1996, interventional studies for preventing geriatric diseases or chronic conditions, and for promoting successful aging have been undertaken in some communities.