Reliability of measurement reliability and optimal number of measurements for mental arithmetic reaction time test

[Purpose] The main objective of this study was to assess the reliability of the method for testing the attention distribution ability of the elderly using mental arithmetic response time. [Participants and Methods] The participants included in the study were 30 healthy elderly people (over 65 years old), 11 males and 19 females, eight of whom had experienced falls in the past year.In the quiet standing position and the free walking state, we recorded the mental calculation response time of the participants by calculating the two-digit plus or minus one-digit values within 100. The test of the two states were tested in 24 hour intervals. [Results] In the quiet standing and free walking state, the correlation coefficient of the mental arithmetic response time group of the elderly was excellent. The intra-group correlation coefficient of mental arithmetic response time of more than three tests under free walking was greater than 0.9. [Conclusion] We found that the mental arithmetic response time can be used to objectively evaluate the ability of attention distribution in the elderly.