Are children participating in a quasi-experimental education outside the classroom intervention more physically active?

Table 2 Physical activity measurement compliance

	EOtC, n (%)	Control, n (%)
Participants	346 (100.0)	317 (100.0)
Valid PA measurements	201 (58.1)	160 (50.5)
Invalid PA measurements	145 (41.9)	157 (49.5)
Accelerometer not returned	12 (3.5)	14 (4.4)
Technical error	10 (2.9)	2 (0.6)
Deliberately removed	18 (5.2)	24 (7.6)
Fallen off	28 (8.1)	25 (7.9)
Unknown if deliberately removed or fallen off	77 (22.3)	92 (29.0)

Valid PA measurements required continuous accelerometer data for seven days with 24 h of wear time per day, starting at midnight on the end of the day the participant had the accelerometer attached. The reason for non-compliance was considered due to a “technical error” if a data file was shorter than the required inclusion period and the accelerometer was still worn at the last time stamp included in a data file. The category “deliberately removed” included reasons such as experiencing a rash at the attachment site and removal of accelerometer due to sports competition. The category “Fallen off” included failing adhesion between tape and skin and accelerometers getting knocked loose by mechanical interference from an external source.

ISSN: 1471-2458