Using Step Activity Monitoring to Characterize Ambulatory Activity in Community‐Dwelling Older Adults

Abstract

To explore the potential of using step activity monitoring to detect differences in ambulatory activity associated with advancing age and declining function in community-dwelling seniors. Cross-sectional pilot study. General communities of Seattle, Washington; Catonsville, Maryland; and Durham, North Carolina. Thirty healthy younger adults, 28 healthy older adults, and 12 older adults reporting functional limitations. Ambulatory activity data were collected over 6 days with the StepWatch 3. Average daily values were calculated for number of steps, number of minutes of activity, number of activity bouts, variability of minute-to-minute activity, and randomness of minute-to-minute activity fluctuations. Healthy older adults engaged in fewer bouts of activity (P=.03) and displayed less-variable activity (P=.02) than younger adults. Older adults reporting functional limitations not only engaged in fewer bouts of activity (P=.009) and less variable activity (P<.001) than younger adults, but also accumulated fewer total steps (P=.003) and minutes of activity (P=.008) and had less-random minute-to-minute activity fluctuations (P=.02). Step activity monitoring data were useful for detecting differences in ambulatory activity according to age and functional limitation. Monitor-based measures reflecting patterns of ambulatory activity show promise for use in studies of physical functioning.