Importance of Assessing Overall Quality of Life in the New Millennium : A Japanese Perspective

在我们的研究项目中，我们最初假设(1)身体健康或身体活力，(2)心理健康或精神活力，(3)经济状况，(4)“其他”变量构成整体生活质量（QoL）的重要维度。身体活力可以用生命年龄、功能适能（或日常生活活动）年龄等来评价，精神活力可以用生活满意度指数、主观生活质量指数、压力指数等来评价。“其他”变量包括食物摄入量、营养状况、身体成分、社会环境等。因此，总体生活质量是健康、独立生活的多维特征，可以作为成功老龄化的良好指标。大量的流行病学证据表明，运动在维持健康相关生活质量方面发挥着重要作用。假设经常参加锻炼或体育活动可以延长日本成年人的健康寿命，我们专门针对老年人制定了一些与健康相关的生活质量指数。与健康相关的生活质量指标包括生命年龄、功能健康年龄、骨矿物质含量、无骨和无脂瘦组织质量、心肺健康、食物和营养状况、生活满意度和抗压力能力。上述每个维度中的许多因素都被制定为一个综合指标，使我们能够为每个人计算一个分数。总体生活质量可以通过综合各个项目得分来评估。总体生活质量评分的有用性将进一步详细研究。

In our research project, we initially assumed that (1) physical health or physical vitality, (2) mental health or mental vitality, (3) economic status, and (4) "other" variables constitute important dimensions of overall quality of life (QoL). Physical vitality is evaluated by vital age, functional fitness (or activities of daily living) age, etc., while mental vitality can be evaluated by life satisfaction index, subjective QoL index, stress index, etc. The "other" variables consist of food intake, nutritional status, body composition, social environment, etc. Thus, overall QoL is a multi-dimensional characteristic for healthy, independent living and may be used as a good indicator for successful aging. Ample epidemiologic evidence suggests that exercise plays an important role in the maintenance of health-related QoL. On the assumption that regular engagement in exercise or physical activities extends the healthy lifespan of Japanese adults, we have developed a number of health-related QoL indices specifically aimed at older people. Those health-related QoL indices consist of vital age, functional fitness age, bone mineral content, bone-free and fat-free lean tissue mass, cardiorespiratory fitness, food and nutritional status, life satisfaction, and resistivity against stress. Many of the above factors in each dimension were formulated as a composite indicator to enable us to compute a score for each individual. Overall QoL can be evaluated by combining the individual item scores. Usefulness of the overall QoL score will be further examined in more detail.