. Author manuscript; available in PMC: 2009 May 1.

Published in final edited form as: Am J Health Promot. 2009;23(4):229–232. doi: 10.4278/ajhp.071211129

Table 1.

Descriptive and Difference Statistics for Physical Activity and Sedentary Behaviors Reported on the Presurveys and Postsurveys^*

	Presurvey Mean (SD)	Postsurvey Mean (SD)	t(df)	p
Physical activity (days/week)	4.01 (2.15)	4.44 (2.07)	4.61 (15)	<0.001
Playing video games/computer use (hours/day)^†	1.68 (1.54)	1.37 (1.35)	−3.84 (15)	0.002
Watching TV/DVDs (hours/day)	1.57 (1.07)	1.41 (1.03)	−2.52 (15)	0.024

t-tests were generated from the final estimation of fixed effects in multilevel modeling. Robust adjustments were made to the standard errors for the calculation of p. Models controlled for age and grade. Unadjusted means are presented. n = 630 students (physical activity), n = 625 students (playing video games/computer use), and n = 626 students (watching TV/DVDs).

^†

Computer use was assessed for purposes other than school work.

SD indicates standard deviation.