Does Wrist-Worn Accelerometer Wear Compliance Wane over a Free-Living Assessment Period? An NHANES Analysis

Abstract

ABSTRACT Purpose Accelerometers are used to objectively measure physical behaviors in free-living environments, typically for ≥7 consecutive days. We examined whether participants experience “wear fatigue”, a decline in wear time day over day, during typical assessment period acquired in a nationally representative sample of 6-80-year-olds in the United States (U.S.). Methods Participants were instructed to wear an ActiGraph GT3X+ on their non-dominant wrist continuously for 7 consecutive days. Participants with seven complete days of recorded data, regardless of wear status, were included in the analyses (N = 13,649). Wear was scored with the Sleep-Wake-and-Nonwear (SWaN) algorithm. Results Participants averaged 1248 ± 3.6 (Mean ± SE) min·day-1 of wear over the assessment but wear time linearly decreased from day 1 (1295 ± 3.2 minutes) to day 7 (1170 ± 5.3 minutes) resulting in a wear fatigue of -18.1 ± 0.7 min·day-1 (β ± SE). Wear fatigue did not differ by sex but varied by age group - highest in adolescents (-26.8 ± 2.4 min·day-1) and lowest in older adults (-9.3 ± 0.9 min·day-1). Wear was lower in evening (18:00-23:59) and early morning (00:00-05:59) compared to the middle of the day and on weekend days compared to weekdays. We verified similar wear fatigue (-23.5 ± 0.7 min·day-1) in a separate sample (N = 14,631) with hip-worn devices and different wear-scoring. Applying minimum wear criteria of ≥10 h·day-1 for ≥4 days reduced wear fatigue to -5.3 mins·day-1 and -18.7 mins·day-1 for the wrist and hip, respectively. Conclusions Patterns of wear suggest non-compliance may disproportionately affect estimates of sleep and sedentary behavior, particularly for adolescents. Further study is needed to determine the impact of wear fatigue on longer assessments.