Article

Many approaches are used to evaluate fall risk. While their
properties and performance vary, most reflect performance at a specific moment or
are based on subjective self-report. OBJECTIVE: To quantify fall risk in the home
setting using an accelerometer. METHODS: Seventy-one community-living older
adults were studied. In the laboratory, fall risk was assessed using
performance-based tests of mobility (eg, Timed Up and Go) and usual walking
abilities were quantified. Subsequently, subjects wore a triaxial accelerometer
on their lower back for 3 consecutive days. Acceleration-derived measures were
extracted from segments that reflected ambulation. These included total activity
duration, number of steps taken, and the amplitude and width at the dominant
frequency in the power spectral density, that is, parameters reflecting
step-to-step variability. Afterwards, self-report of falls was collected for 6
months to explore the predictive value. RESULTS: Based on a history of 2 or more
falls, subjects were classified as fallers or nonfallers. The number of steps
during the 3 days was similar (P = .42) in the fallers (7842.1 +/- 6135.6) and
nonfallers (9055.3 +/- 6444.7). Compared with the nonfallers, step-to-step
consistency was lower in the fallers in the vertical axis (amplitude fallers,
0.58 +/- 0.22 psd; nonfallers, 0.71 +/- 0.18 psd; P = .008); in the mediolateral
axis, step-to-step consistency was higher in the fallers (P = .014). The 3-day
measures improved the identification of past and future falls status (P < .005),
compared to performance-based tests. CONCLUSIONS: Accelerometer-derived measures
based on 3-day recordings are useful for evaluating fall risk as older adults
perform daily living activities in their everyday home environment.

Langue : ANGLAIS