. Author manuscript; available in PMC: 2015 Sep 15.

Published in final edited form as: J Phys Act Health. 2013 Jan 30;11(2):348–358. doi: 10.1123/jpah.2012-0043

Table 4.

Mixed Model Estimates^a (95% CI) of MVPA (Minutes/Day), Measured by Actical Physical Activity Monitors, by Study Group

	Workbook	Internet	Difference (95% CI)	P-value
Weekly average
Baseline	72.45 (64.79, 80.10)	73.64 (66.01, 81.27)	1.19 (−9.60, 11.99)	0.827
Week 6	66.20 (58.66, 73.75)	67.11 (59.53, 74.70)	0.91 (−9.78, 11.60)	0.867
Week 12	68.47 (60.61, 76.34)	68.90 (61.04, 76.76)	0.43 (−10.68, 11.53)	0.939
Change from baseline
Week 6	−6.24 (−12.73, 0.24) 0.059	−6.53 (−12.98, −0.08) 0.047	−0.29 (−9.37, 8.80)	0.951
Week 12	−3.97 (−9.80, 1.85) 0.179	−4.74 (−11.49, 2.00) 0.166	−0.77 (−9.63, 8.09)	0.865
Adjusted^b change from baseline
Week 6	−1.96 (−8.91, 4.98) P = .577	−2.43 (−8.72, 3.86) P = .446	−0.47 (−8.46, 7.52)	0.908
Week 12	3.44 (−5.34, 12.23) P = .441	1.81 (−6.99, 10.61) P = .685	−1.63 (−9.40, 6.14)	0.679

Random family effect included to account for multiple children per family. Kronecker (UN@CS) covariance structure used for repeated measures within an individual (3 time points × up to 6 daily measurements per time point). Covariance matrix estimated separately for each study group. Satterthwaite correction for denominator degrees of freedom.

Adjusted for calendar month, age, sex, and baseline BMI-for-age z score.