Screen-based sedentary behavior and associations with functional strength in 6–15 year-old children in the United States

Table 2 Number of hours per day children reported watching TV watching or playing computer/ video games

	0 Hours	<1 Hour	1 Hour	2 Hours	3 Hours	4 Hours	5+ Hours	Mean (95 % CI)^a (Minutes)
TV Time^b	% of Sample
6-9 y	1	17	30	32	12	4	3	103 (91 – 115)***
10-12 y	1	14	21	34	15	6	8	125 (111 – 138)
13-15 y	2	12	21	29	21	9	8	130 (121 – 139)
Full sample (6–15 y)	1	15	25	32	16	6	6	117 (109 – 126)
Computer Time^c
6-9 y	12	41	26	12	5	2	2	61 (54 – 67)***
10-12 y	12	31	24	17	10	3	3	78 (67 – 88)
13-15 y	10	23	16	20	14	10	8	114 (99 – 125)
Full sample (6–15 y)	11	33	23	16	9	5	4	80 (73 – 88)

^aLinear trends across the three age categories for hours of TV or computer time were tested using simple linear regression models accounting for the survey design of the 2012 NNYFS. Due to the potential of rounding and discrete nature of these variables, a non-parametric test extending the Wilcoxon rank-sum test was conducted using STATA (version 13.1, 2013, StataCorp, College Station, TX) to test for trends across the ordered age groups to confirm the robustness of the findings from the linear regression models
^bTelevision time estimated based on self-report of the average hours per day over the last 30 days
^cComputer or video game time outside of work or school estimated based on self-report of the average hours per day over the last 30 days
***Indicates a significant linear trend (p < 0.001) across age groups for both the linear regression model (regression coefficient) and the extension of the Wilcoxon-rank sum (non-parametric) test