科研之友
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摘要
Background: Step counters have been used to observe activity and support physical activity, but there is limited evidence on their accuracy. Objective: The purpose was to investigate the step accuracy of the Fitbit Zip (Zip) in healthy adults during treadmill walking and in patients with cardiac disease while hospitalised at home. Methods: Twenty healthy adults aged 39 (+/-)13.79 (Mean +/- sd) wore four zips while walking on a treadmill at different speeds (1.7- 6.1 km/ hour), and 24 patients with cardiac disease (age 67 +/- 10.03) wore a Zip for 24 hours during hospitalisation and for 4 weeks thereafter at home. A Shimmer3 device was used as a criterion standard. Results: At a treadmill speed of 3.6 km/ hour, the relative error (+/- SD) for the Zips on the upper body was - 0.02 +/- 0.67 on the right side and - 0.09 (0.67) on the left side. For the Zips on the waist, this was 0.08 +/- 0.71 for the right side and - 0.08 (0.47) on the left side. At a treadmill speed of 3.6 km/ hour and higher, the average per cent of relative error was < 3%. The 24- hour test for the hospitalised patients showed a relative error of - 47.15 +/- 24.11 (interclass correlation coefficient (ICC): 0.60), and for the 24- hour test at home, the relative error was - 27.51 +/- 28.78 (ICC: 0.87). Thus, none of the 24- hour tests had less than the expected 20% error. In time periods of evident walking during the 24 h test, the Zip had an average per cent relative error of < 3% at 3.6 km/ hour and higher speeds. Conclusions: A speed of 3.6 km/ hour or higher is required to expect acceptable accuracy in step measurement using a Zip, on a treadmill and in real life. Inaccuracies are directly related to slow speeds, which might be a problem for patients with cardiac disease who walk at a slow pace.
- 出版日期2017-3
