Hurricane Sally Update
The ActiGraph office is open, and we have resumed normal operations as of Monday, September 21st. Shipping delays are still possible as our community recovers from the storm. If you need immediate assistance, please contact us by email at firstname.lastname@example.org and we will respond as quickly as possible. Thank you for your continued support.
Challenges and opportunities for measuring physical activity and sedentary behaviour in children and adolescents: What do we know and how can we improve compliance?
- Presented on 2015
Introduction: This study examined agreement between activPAL3 (AP) and ActiGraph (AG) wrist and hip cut-points for assessing sedentary behaviour (SB) among 5-12 year-old children using direct observation (DO) as the criterion.
Methods: 30 children (9.2±2.1y, 53.3% boys) wore AG on both wrists and the right hip and a thigh-mounted AP while completing 15 5min semi-structured sedentary, light, and moderate-to-vigorous-intensity activities. Posture was classified by AP and coded from video for DO (1s epochs) during activities and transitions (151.9min±36.6). SB was defined using AG wrist cut-points developed for the vertical axis (VA) and vector magnitude by Crouter et al. (CR) and Kim et al. (KI), and for the hip (AG_hip, 25 counts(c)/15s). Analyses examined equivalence of time estimates (equivalence testing), individual level bias (Bland-Altman plots) and misclassification (receiver operating characteristic (ROC) curves).
Results: Although none of the methods were equivalent with DO (68.5min: equivalence range=61.7-75.4), AP (64.5min: 90%CI=58.6-70.5), CR_VA ≤.35c/5s; 64.1min: 90%CI=58.7-69.4), KI_VA (≤.1756c/60s) dominant (65.0min: 90%CI=59.4-70.6) and non-dominant (63.8min: 90%CI=58.1-69.6) demonstrated a small underestimation, while AG_hip overestimated SB (80.3min: 90%CI=73.0-87.6). Mean differences were smaller and 95% limits of agreement narrower for AP (4.0min: -9.7-17.7), CR_VA (4.5min: -14.0-23.0), KI_VA dominant (3.6min: -11.2-18.3) and non-dominant (4.7min: -11.6-14.2), compared to AG_hip (-11.8min: -30.0-6.5). Although area under the ROC curve for AP (0.995) and KI_VA dominant (0.884) and non-dominant (0.865) were higher than AG_Hip (0.853), CR_VA (0.787) was less accurate.
Conclusion: On group- and individual-level tests, the AG KI_VA wrist cut-point demonstrated similar agreement to AP and better agreement than AG_hip for estimating SB.