Comparison of physical behavior estimates from three different thigh-worn accelerometers brands: a proof-of-concept for the Prospective Physical Activity, Sitting, and Sleep consortium (ProPASS)

Table 3 Physical behavior duration and step count per 24-h (1440 min) free-living (n = 19); mean ± 1SD

Accelerometer	Lie/Sit	Stand	Move	Walk	Run	Stairs	Cycle	Steps
	(in minutes)		(in minutes)					(No. of steps)
Actigraph GT3X+ ^(a)	1063 ± 112	190 ± 82	66 ± 22	78 ± 21	3 ± 9	6 ± 3	33 ± 16	9920 ± 3097
ActivPAL Micro4 ^(a)	1062 ± 113	193 ± 87	63 ± 20	78 ± 20	3 ± 9	5 ± 3	34 ± 17	9827 ± 2971
Axivity AX3 ^(a)	1063 ± 113	192 ± 85	66 ± 20	76 ± 20	3 ± 9	6 ± 2	34 ± 16	9597 ± 2895
	Lie/Sit	Stand	Move	Walk	Run	Stairs	Cycle	Steps
AbsSD ^(b)	1.2 ± 1.4	3.4 ± 3.2	3.5 ± 3.1	1.9 ± 1.5	0.1 ± 0.1	1.2 ± 1.1	1.9 ± 2.2	282 ± 276
CV ^(c)	0.001	0.02	0.06	0.03	0.19	0.19	0.07	0.03

^(a)Behavior classifications are based on those defined by Skotte et al. 2014 [1]. Step count was derived according to Ingebrigtsen et al. 2013 [10]. Values are computed from the daily average duration of free-living accelerometry measurements of up to a maximum of 6 days. Accelerometers from three different brands (Actigraph GT3+, Axivity AX3, and ActivPAL Micro4) were placed in a vertical line on the midsection of the thigh. The order of placement followed a randomized partial counterbalance design
^(b)Mean SD is calculated as the average standard deviation in activity durations between all three devices, for each participant
^(c)\( \mathrm{CV}=\upsigma /\overline{\mathrm{A}} \); where σ = SD and \( \overline{A} \) = the mean activity duration between all three devices for each participant

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