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 Variable Total sample (n = 419) Page 4 of 10 Internal consistency Cronbach alpha Socio-demographic characteristics Gender (%) Men Women Age (mean [SD]) Educational level (%) No college/university degree College/university degree Employment status (%) Unemployed/retired Employed Occupation (%) Blue-collar White-collar Body Mass Index (mean [SD]) Home-environmental factors (mean [SD]) Number of TVs Size of largest TV seta Number of computers Psychosocial factors (mean [SD]) Pros reducing TV viewing (sum of different items)b I think watching TV is boring Watching TV takes time away from doing other more important things I would feel lazy and sluggish if I watched TV for many hours Watching TV sometimes hurts my eyes and gives me a headache Cons reducing TV viewing (sum of different items)b I enjoy watching TV for many hours at a time Watching TV is my way to escape from the world Watching TV is one of my favorite types of entertainment I find sitting and watching TV very relaxing Family social norm TV viewingb My family members think I spend too much time watching TV Friends social norm TV viewingb My friends think I spend too much time watching TV Self-efficacy reducing TV viewing (sum of different items)c Turn off the TV even when there is a program on I enjoy Limit my TV time to one hour a day Leave the room where the TV is on even if others are watching TV Plan ahead of time what TV shows I will watch during the week 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 Family social norm Internet useb 47.3 52.7 48.50 (12.10) 43.3 56.7 29.4 70.6 19.7 80.3 24.61 (3.90) 1.65 (0.89) 2.75 (1.04) 1.75 (1.15) 2.59 (0.68) 2.51 (0.96) 2.80 (1.22) 3.52 (1.20) 1.53 (0.85) 2.54 (0.85) 2.64 (1.13) 2.18 (1.09) 2.18 (1.14) 3.17 (1.05) 1.62 (0.90) 1.46 (0.72) 3.76 (0.84) 3.25 (1.15) 3.59 (1.27) 4.20 (0.94) 4.01 (1.14) 2.51 (0.80) 2.59 (1.18) 2.40 (1.32) 3.39 (1.37) 1.58 (0.95) 1.79 (0.74) 1.85 (0.99) 1.65 (0.94) 1.66 (0.93) 2.13 (1.12) 0.50 0.77 0.73 0.50 0.77