Physical Activity Monitoring In the LIFE Study Using the Actigraph Accelerometer

在LIFE试点研究中，被分配到运动组的参与者的主要干预措施将是散步。根据治疗方案，在头六个月里，多达一半的步行量将在家中或无人监督的环境中进行。在接下来的六个月里，对于大多数参与者来说，至少75%的指定步行将是无人监督的。为了知道这种干预是否完成，LIFE的调查人员需要证明运动组的参与者与健康衰老组的参与者相比，步行量显著增加。目前的方案包括使用计步器、日志和CHAMPS问卷来告知研究人员每个研究参与者的活动概况。虽然所有这些测量工具都可能提供有用的数据，但没有一种被证明能够准确客观地评估老年人的日常身体活动情况。Actigraph是一款小型固态加速度计/记录仪（6.6 x 4.3 x 2.5 cm.， 70克），可以连续存储移动次数x运动变化率（加速度）长达一个月（大约电池寿命）。它以指定的时间间隔（通常设置为一分钟）存储这些计数。对于LIFE，该监测器将佩戴在每个参与者的右臀部。试验现已完成，活动记录仪数据正在清理和分析中。关于研究结果的论文正在准备中。

The major intervention in the LIFE pilot study for participants assigned to the exercise group will be walking. According to the treatment protocol, during the first six months as much as half of their increase in walking will be carried out at home or in a non-supervised setting. During the second six months, at least 75% of the assigned walking will be non-supervised for most participants. To know if this intervention was accomplished, LIFE investigators need documentation that a significant increase in walking took place in the exercise participants versus the healthy aging class participants. Currently the protocol includes the use of pedometers, logs and the CHAMPS questionnaire to inform the investigators about the activity profile of each study participant. While all of these measurement tools are likely to provide useful data, none have been proven to provide an accurate and objective assessment of the daily physical activity profile of older, somewhat frail persons. The Actigraph is a small solid-state accelerometer/recorder (6.6 x 4.3 x 2.5 cm., 70 grams) that can store the number of times it moves x the rate of movement change (acceleration) on a continuous basis for up to a month (approximate battery life). It stores these counts for specified times intervals, usually set at one-minute. For LIFE, this monitor will be worn on the right hip of each participant. The trial is now complete and actigraph data are being cleaned and analyzed. A paper on the results is in preparation.