Table 1

Personal characteristics and characteristics of online behaviors of the study population of 5,122 Shanghai adolescents
Variables N Percentage (%) Internet use %(Nusing internet/ Nwhole)c Total Scorea(mean ± SD) Internet addictionb%(Ninternet addiction/ Nwhole)d
Gender (missing n=8)
 Female (ref.) 2580 50.4% 95.1% (2453 / 2580) 117.0 ± 38.1 6.4% (164 / 2580)
 Male 2534 49.6% 92.6% (2347 / 2534)**e 122.4 ± 43.5***e 11.3% (285 / 2534)***e
Grade (missing n=1)
 Junior high school students (ref.) 1915 37.4% 92.6% (1774 / 1915) 110.3 ± 42.4 7.1% (135 / 1915)
 Senior high school students 3206 62.6% 94.6% (3033 / 3206)** 125.3 ± 39.0*** 9.8% (315 / 3206)**
School type (missing n=2)
 Junior high school (ref.) 1907 37.2% 92.7% (1768 / 1907) 110.4 ± 42.3 7.1% (135 / 1907)
 Key senior high school 1096 21.4% 94.5% (1036 / 1096) 120.2 ± 37.7*** 6.1% (67 / 1096)
 Ordinary senior high school 1102 21.5% 93.3% (1028 / 1102) 122.9 ± 40.9*** 9.4% (104 / 1102)*
 Vocational senior high school 1015 19.8% 96.0% (974 / 1015)* 133.1 ± 37.3*** 14.2% (144 / 1015)***
Adolescent monthly money spending (missing n=9)
 < 100 RMB (ref.) 3028 59.1% 92.6% (2805 / 3028) 112.2 ± 41.1 5.6% (168 / 3028)
 100~300 RMB 1373 26.8% 95.7% (1314 / 1373)*** 128.9 ± 38.0*** 12.5% (172 / 1373)***
 ≥300 RMB 712 13.9% 95.7% (681 / 712)*** 133.5 ± 38.3*** 15.3% (109 / 712)***
Residential or commuter students (missing n=4)
 Commuter students (ref.) 4667 91.1% 93.7% (4372 / 4667) 119.2 ± 41.3 8.7% (407 / 4667)
 Residential students 451 8.8% 96.0% (433 / 451)* 125.2 ± 35.6** 9.5% (43 / 451)
Academic achievement (missing n=16)
 Very good (ref.) 324 6.3% 92.3% (299 / 324) 113.1 ± 42.2 4.0% (13 / 324)
 Relatively good 1386 27.1% 94.4% (1308 / 1386) 112.9 ± 38.3 5.6% (78 / 1386)
 General 2835 55.4% 94.6% (2682 / 2835) 122.3 ± 39.4*** 8.9% (253 / 2835)***
 Relatively &very bad 561 11.0% 89.7% (503 / 561) 126.8 ± 50.7*** 18.9% (106 / 561)***
Main purpose of using internet (missing n=15)
 Academic learning (ref.) 720 14.1% 100% 109.3 ± 26.8 1.4% (10 / 720)
 Only browsing news or emails 881 17.2% 100% 117.3 ± 25.7*** 2.5% (22 / 881)
 Playing games 1003 19.6% 100% 140.7 ± 28.6*** 20.1% (202 / 1003)***
 Real-time chatting 667 13.0% 100% 132.5 ± 24.6*** 8.1% (54 / 667)***
 Wandering aimlessly online 1546 30.2% 100% 128.9 ± 29.2*** 10.2% (158 / 1546)***
Place of using internet (missing n=24)
 School (ref.) 314 6.1% 100% 115.2 ± 29.4 4.5% (14 / 314)
 Residences of classmates or relatives 705 13.8% 100% 120.7 ± 27.6* 5.4% (38 / 705)
 Home 3586 70.0% 100% 128.5 ± 29.4*** 10.3% (369 / 3586)**
 Internet bar 203 4.0% 100% 137.6 ± 25.9*** 14.3% (29 / 203)***
Total hours online for a whole week (missing n=16)
 <7 hours (ref.) 2812 54.9% 100% 117.7 ± 27.7 4.1% (114 / 2812)
 7~14 hours 970 18.9% 100% 133.2 ± 26.6*** 11.8% (114 / 970)***
 14~21 hours 414 8.1% 100% 140.9 ± 24.1*** 15.5% (64 / 414)***
 21~28 hours 242 4.7% 100% 145.8 ± 23.9*** 22.3% (54 / 242)***
 >28 hours 378 7.4% 100% 151.1 ± 26.9*** 27.3% (103 / 378)***
Hours online per weekday (missing n=21)
 ≤2 hours (ref.) 3390 70.5% 100% 121.9 ± 29.1 6.9%(235/3390)
 2~4 hours 756 15.7% 100% 134.3 ± 24.8*** 10.6%(80/756)**
 4~6 hours 357 7.4% 100% 139.5 ± 26.9*** 17.1%(61/357)***
 6~8 hours 113 2.3% 100% 143.0 ± 28.0*** 23.0%(26/113)***
 ≥8 hours 195 4.0% 100% 151.4 ± 26.7*** 24.2%(47/195)***
Hours online on each Saturday/Sunday (missing n=17)
 ≤2 hours (ref.) 1835 35.8% 100% 114.5 ± 28.1 3.4% (63 / 1835)
 2~4 hours 1457 28.5% 100% 125.6 ± 25.8*** 6.3% (92 / 1457)***
 4~6 hours 668 13.0% 100% 136.5 ± 25.2*** 12.0% (80 / 668)***
 6~8 hours 351 6.9% 100% 143.8 ± 24.5*** 20.2% (71 / 351)***
 ≥8 hours 504 9.8% 100% 150.7 ± 27.5*** 28.4% (143 / 504)***

a total score: total score of DRM-52 scale.

b internet addiction: defined when the total score of DRM-52 scale ≥163.

c %(Ninternet use /N whole): the rates of internet use was calculated as the ratio of the numbers of internet-use adolescents to the numbers of whole adolescent samples in that group.

d %(Ninternet addiction / N whole): the rates of AIA was calculated as the ratio of the numbers of internet-addicted adolescents to the numbers of whole adolescent samples in that group.

ep values for the comparison of total scores were calculated by one-way ANOVA, p values for the comparison of the rates of AIA were calculated by chi-square.

*p-values<0.05; **p-values<0.01; ***p-values<0.001 (compared with reference groups).

Xu et al.

Xu et al. BMC Public Health 2012 12:1106   doi:10.1186/1471-2458-12-1106

Open Data