The authors explored using the ActiGraph accelerometer to differentiate activity levels between participants in a physical activity (PA, n = 54) or “successful aging” (SA) program (n = 52). The relationship between a PA questionnaire for older adults (CHAMPS) and accelerometry variables was also determined. Individualized accelerometry-count thresholds (ThreshIND) measured during a 400-m walk were used to identify “meaningful activity.” Participants then wore the ActiGraph for 7 days. Results indicated more activity bouts/day ≥10 min above ThreshIND in the PA group than in the SA group (1.1 ± 2.0 vs 0.5 ± 0.8, p = .05) and more activity counts/day above ThreshIND for the PA group (28,101 ± 27,521) than for the SA group (17,234 ± 15,620, p = .02). Correlations between activity counts/hr and CHAMPS ranged from .27 to .42, p < .01. The ActiGraph and ThreshIND might be useful for differentiating PA levels in older adults at risk for mobility disability.
Pruitt, King, and Haskell are with the Stanford Prevention Research Center, Stanford University School of Medicine, Stanford, CA. Glynn and Aiken are with the Dept. of Epidemiology, University of Pittsburgh, Pittsburgh, PA. Guralnik is with Epidemiology, Demography and Biometry, National Institute on Aging, Bethesda, MD. Miller is with the Dept. of Health and Exercise Science, Wake Forest University, Winston-Salem, NC.