Van Dyck et al. BMC Public Health 2011, 11:668 http://www.biomedcentral.com/1471-2458/11/668 Table 1 Sample characteristics and internal consistency of psychosocial factors (Continued) My family members think that I spend too much time using the Internet Friends social norm Internet useb My friends think that I spend too much time using the Internet Self-efficacy reducing Internet use (sum of different items)c Turn off the computer even when I am doing something funny Limit my leisure-time Internet use to one hour a day Plan ahead of time how much time I will spend on leisure-time Internet use daily Sedentary behaviors (mean [SD]) TV viewing time (min/day) Leisure-time Internet use (min/day) 1.45 (0.78) 1.31 (0.61) 4.14 (0.91) 3.93 (1.10) 4.38 (0.95) 4.11 (1.18) 128.40 (76.74) 43.57 (46.57) Page 5 of 10 0.78 a Size of the largest TV was positively scored on a five-point scale (1-5), ranging from 39 cm to 139 cm b pros, cons, family social norm and friends social norm were positively scores on a five-point scale (1-5), ranging from ‘strongly disagree’ to ‘strongly agree’ c self-efficacy was positively scored on a five-point scale (1-5), ranging from ‘I think this is very difficult’ to ‘I do not think this is difficult at all’ SD = standard deviation Table 2 Bivariate correlations of home-environmental and psychosocial factors with sedentary behaviors Variable r TV viewing Home-environmental factors (mean [SD]) Number of TVs 0.15*** Size of largest TV seta 0.13** Number of computers Psychosocial factors (mean [SD]) Pros reducing TV viewing (sum of different items)b -0.31*** I think watching TV is boring -0.29*** Watching TV takes time away from doing other more important things -0.13** I would feel lazy and sluggish if I watched TV for many hours -0.35*** Watching TV sometimes hurts my eyes and gives me a headache 0.02 Cons reducing TV viewing (sum of different items)b 0.47*** I enjoy watching TV for many hours at a time 0.54*** Watching TV is my way to escape from the world 0.22*** Watching TV is one of my favorite types of entertainment 0.36*** I find sitting and watching TV very relaxing 0.30*** Family social norm TV viewingb My family members think I spend too much time watching TV 0.34*** Friends social norm TV viewingb My friends think I spend too much time watching TV 0.35*** Self-efficacy reducing TV viewing (sum of different items)c -0.49*** Turn off the TV even when there is a program on I enjoy -0.24** Limit my TV time to one hour a day -0.65*** Leave the room where the TV is on even if others are watching TV -0.28** Plan ahead of time what TV shows I will watch during the week -0.25** Pros reducing Internet use (sum of different items)b I think using the Internet is boring Using the Internet takes time away from doing other more important things I would feel lazy and sluggish if I used the Internet for many hours Using the Internet sometimes hurts my eyes and gives me a headache Cons reducing Internet use (sum of different items)b I enjoy using the Internet for many hours at a time The Internet is my way to escape from the world Using the Internet is one of my favorite forms of entertainment I find sitting and using Internet very relaxing r Internet use 0.18*** -0.16** -0.39*** 0.09 -0.19*** -0.13* -0.31*** 0.51*** 0.30*** 0.49*** 0.43***