title: Comparison of older adults' steps per day using NL-1000 pedometer and two GT3X+ accelerometer filters.
abstract: The purpose of this study was to compare the steps/d derived from the ActiGraph GT3X+ using the manufacturer's default filter (DF) and low-frequency-extension filter (LFX) with those from the NL-1000 pedometer in an older adult sample. Fifteen older adults (61-82 yr) wore a GT3X+ (24 hr/day) and an NL-1000 (waking hours) for 7 d. Day was the unit of analysis (n = 86 valid days) comparing (a) GT3X+ DF and NL-1000 steps/d and (b) GT3X+ LFX and NL-1000 steps/d. DF was highly correlated with NL-1000 (r = .80), but there was a significant mean difference (-769 steps/d). LFX and NL-1000 were highly correlated (r = .90), but there also was a significant mean difference (8,140 steps/d). Percent difference and absolute percent difference between DF and NL-1000 were -7.4% and 16.0%, respectively, and for LFX and NL-1000 both were 121.9%. Regardless of filter used, GT3X+ did not provide comparable pedometer estimates of steps/d in this older adult sample.
authors.affiliation: Pennington Biomedical Research Center, Baton Rouge, LA.
authors.forename: Tiago V
authors.initials: TV
authors.lastname: Barreira
authors.forename: Robert M
authors.initials: RM
authors.lastname: Brouillette
authors.forename: Heather C
authors.initials: HC
authors.lastname: Foil
authors.forename: Jeffrey N
authors.initials: JN
authors.lastname: Keller
authors.forename: Catrine
authors.initials: C
authors.lastname: Tudor-Locke
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018670:Monitoring, Ambulatory / Q000295:instrumentation*; D016138:Walking / Q000502:physiology*