Validity of 2 Devices for Measuring Steps Taken by Older Adults in Assisted-Living Facilities

Background: This 2-part study examined validity of selected motion sensors for assessing physical activity in older adults residing in assisted-living communities. Methods: Twenty-one older adults (mean age = 78.6 +/- 13.1 years) wore the StepWatch 3 Step Activity Monitor (SW3) and the Yamax Digi-Walker SW-200 pedometer (DW). Part I compared accuracy of these devices for measuring steps taken over 161 m. Part II compared devices over a 1-day (24-hour) period. Results: In part I, the DW recorded 51.9% (r(2) = -.08, P = .75) and the SW3 recorded 102.6% (r(2) = .99, P < .001) of steps. In part II, the DW measured significantly fewer steps (1587 +/- 1057 steps) than did the SW3 (6420 +/- 3180 steps). Conclusions: The SW3 pedometer was more accurate in counting steps and recorded higher 24-hour step counts than the DW pedometer. Thus, the SW3 is a valid research instrument for monitoring activity in the assisted-living population.