Responsiveness of motion sensors to detect change in sedentary and physical activity behaviour

Abstract

Background The purpose of this study was to determine the responsiveness of two motion sensors to detect change in sedentary behaviour (SB) and physical activity (PA) during an occupational intervention to reduce sitting time. Methods SB and PA were assessed using a hip-worn Actigraph GTX3 (AG) and a thigh-worn activPAL (AP) during three consecutive workdays throughout baseline and intervention periods. Mean scores at baseline and intervention were estimated by hierarchical linear models (HLM) with robust SEs, adjusting for random variance of average scores between participants. Change scores (mean baseline minus mean intervention) were calculated for each device. Response to change was assessed for each device using the standardised response mean. Results 67 adults (45±11 years; 29.3±7.7 kg/m2) wore the acceleration-based motion sensors for 8.3 (SD=1.2) and 8.3 (SD=1.1) h during the baseline and intervention periods, respectively. HLM showed that AP sitting/lying time (−16.5 min, −5%), AP stepping (+7.5 min, 19%), AP steps/day (+838 steps/day, +22%), AP sit-to-stand transitions (+3, +10%), AG SB (−14.6 min, −4%), AG lifestyle moderate-intensity PA (LMPA, +4 min, +15%) and AG MPA (+3 min, 23%) changed significantly between the baseline and the intervention period. Standardised response means for AP sitting/lying time, stepping, steps/day, sit-to-stand transitions and AG SB, LMPA and MPA were above 0.3, indicating a small but similar responsiveness to change. Conclusions Responsiveness to change in SB and PA was similar and comparable for the AP and AG, indicating agreement across both measurement devices.

Sensitivity to Change of Objectively-Derived Measures of Sedentary Behavior

“…In that study, changes were assessed by comparing one baseline day with 1 day of an intervention condition that involved reducing and breaking up sedentary time. Similarly, in a single-group design with a brief intervention that involved computer and device-based prompts to interrupt sedentary time, Swartz et al (2014) observed similar sensitivity, assessed as standardized response mean, for activPAL (0.30), and ActiGraph (0.32) monitors in total sedentary time. Sit-stand transitions as measured by the activPAL was the only sedentary accumulation measure for which sensitivity was reported; its standardized response mean (0.40) was similar or slightly higher than was observed for total sedentary time.…”

“…Previous studies (Lyden et al, 2012;Swartz, Rote, Cho, Welch, & Strath, 2014) examining responsiveness to change of measures derived from body worn sensors have only considered a single design (within subject) and mainly reported sensitivity to change in total sedentary time. The aim of this article is to give a more complete assessment of the sensitivity to change of objective measures of sedentary time for different study designs, time frames, and populations.…”

Validity of GT3X and Actiheart to estimate sedentary time and breaks using ActivPAL as the reference in free-living conditions

“…Rather, accelerometers estimate sedentary time based on a lack of movement (<100 counts min À1 ), which may often erroneously incorporate light PA behaviors (standing) as sedentary time. One study found GT3X to accurately detect changes in sedentary time and PA comparable with ActivPAL [13]. Conversely, evidence suggests that the GT3X may not be able to identify breaks in sedentary time given its biased and imprecise estimates of total sedentary time [5].…”

Responsiveness of Physical Activity Measures Following Exercise Programs after Total Knee Arthroplasty

“…[23–25, 35] Responsiveness indices from studies on measures from ACT ranged from 0.18 to 0.36 in subjects with type-2 diabetes,[23] nonworking older adults,[24] and sedentary healthy adults. [25] One study on the CHAMPS questionnaire in healthy older adults found responsiveness indices of 0.33 and 0.37 in moderate-intensity PA and light-to-moderate PA respectively. [35] The small responsiveness of PA measures across the studies not only highlight the difficulty to change PA behavior, but also support the notion that assessment of changes in PA over-time at the group-level may not be adequate.…”

“…[12, 23–25] Additionally, studies have not concurrently compared responsiveness across these three measurement tools, which will provide information for evidence-based instrument selection to assess changes in PA behavior over-time in individuals with osteoarthritis of the lower extremities. Therefore, this study aims to estimate and compare the responsiveness of the ACT, SWA, and CHAMPS in assessing light-, moderate- and vigorous-intensity PA following a rehabilitation program after TKA.…”