Change in children’s physical activity and sedentary time between Year 1 and Year 4 of primary school in the B-PROACT1V cohort

Table 4 Change in parent physical activity accelerometer measures between Year 1 and Year 4 for all who participated at Year 1 or Year 4 using multiple imputation of missing values (N = 1837)^a

Physical Activity Measure	Female parent (N = 1837)				Male parent (N = 1837)
	Year 1	Year 4	Change Year 1 to Year 4		Year 1	Year 4	Change Year 1 to Year 4
	Mean (SD)	Mean (SD)	Mean (95% CI)	P for difference^*	Mean (SD)	Mean (SD)	Mean (95% CI)	P for difference^*
Counts per minute overall	405.9 (141.4)	399.5 (139.5)	−6.4 (−17.2, 4.4)	0.23	409.1 (144.0)	419.8 (164.8)	10.7 (−14.2, 35.5)	0.37
Counts per minute on a weekday	420.0 (141.9)	415.0 (141.7)	−5.0 (−17.5, 7.4)	0.42	415.3 (167.6)	421.3 (178.6)	6.1 (−30.2, 42.3)	0.72
Counts per minute on a weekend day	383.1 (217.7)	372.9 (210.5)	−10.2 (−30.8, 10.3)	0.31	397.2 (256.2)	423.2 (257.2)	26.0 (−40.4, 92.4)	0.39
Average sedentary minutes per day overall	509.2 (77.1)	535.0 (106.1)	25.8 (16.2, 35.3)	<0.001	546.0 (92.1)	555.5 (113.3)	9.5 (−11.8, 30.9)	0.34
Average sedentary minutes per weekday	523.0 (91.4)	547.9 (118.9)	24.9 (13.5, 36.3)	<0.001	565.8 (117.2)	571.0 (133.2)	5.2 (−22.0, 32.5)	0.68
Average sedentary minutes per weekend day	485.8 (101.5)	510.7 (128.1)	24.9 (5.8, 43.9)	0.01	518.3 (127.1)	528.4 (160.2)	10.1 (−25.3, 45.6)	0.54
Average MVPA minutes per day overall	48.2 (19.7)	48.5 (20.1)	0.3 (−1.1, 1.8)	0.67	51.0 (21.7)	54.1 (24.1)	3.0 (−0.2, 6.2)	0.06
Average MVPA minutes per weekday	52.7 (24.3)	52.6 (24.7)	−0.1 (−2.1, 1.9)	0.94	54.5 (28.7)	56.8 (32.3)	2.3 (−2.6, 7.1)	0.33
Average MVPA minutes per weekend day	41.1 (26.5)	41.6 (25.8)	0.5 (−2.5, 3.5)	0.73	45.6 (36.7)	49.4 (37.6)	3.8 (−8.8, 16.4)	0.49

1016 children had no valid male parent accelerometer data; 361 had valid data for Year 1 but not Year 4 (321 complete); 323 had valid data for Year 4 but not Year 1 (281 complete); 137 had valid data at both time points (6 complete for Year 4 only, 9 complete for Year 1 only, 122 complete in both years (included in Additional file 3: Table S3))
^a558 children had no valid female parent accelerometer data; 524 had valid data for Year 1 but not Year 4 (456 complete); 436 had valid data for Year 4 but not Year 1 (379 complete); 319 had valid data at both time points (21 complete for Year 4 only, 21 complete for Year 1 only, 268 complete in both years (included in Additional file 3: Table S3))
^* P-value obtained from a paired t-test that the difference in the means of the Year 1 and Year 4 values is 0, using robust standard errors to account for clustering by school

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