Assessment of 24-hour physical behaviour in adults via wearables: a systematic review of validation studies under laboratory conditions

Table 2 Summary of data extraction: Participant and study characteristics

Category		Total (N = 545)	Biological State (N = 80)	Posture/Activity Type (N = 70)	Intensity (N = 420)
Publication year	≤ 1999	15	4	2	9
	2000–2010	104	17	8	82
	≥ 2011	426	59	60	329
Study location ^a	Africa	1			1
	Asia	31	6	1	24
	Europe	191	17	45	145
	North America	268	43	18	214
	Australia/Oceania	50	14	6	32
	South America	4			4
Number of participants [N] ^b	≤ 19	119	15	27	85
	20–50	348	46	35	282
	≥ 51	78	19	8	53
Age [years, mean age] ^c	18–64	470	74	56	361
	≥ 65	72	6	13	57
Sex [female %] ^d	0–25	57	11	11	37
	26–74	386	57	47	299
	75–100	69	9	10	55
Protocol type	Activities of daily life	151		56	114
	Exercise	19			19
	Others	100		18	88
	Sleep	81	80		1
	Treadmill	230		18	222
	Walking and running	181		17	170
Criterion measure	3-Dimensional Gait analysis	1			1
	Compendium	3			3
	Diary	2	1		1
	Direct calorimetry	1			1
	Indirect calorimetry	215		7	213
	Observation (direct)	131		22	112
	Observation (video)	138		41	111
	Polysomnography	79	79
	Video-electroencephalography	1	1
	Wearable	43		3	39
Statistical analyses	Epoch-by-epoch	105	54	31	28
	Person/study level	493	76	54	385

^a Three studies were not included in the summary statistics due to the lack of study location information; ^b One study was not included in the summary statistics due to the lack of sample size information; ^c Five studies were not included in the summary statistics due to the lack of age information; ^d Twenty-seven studies were not included in the summary statistics due to the lack of sex information

ISSN: 1479-5868