From: Sleep problems, sleep duration, and use of digital devices among primary school students in Japan
 | Unadjusted | Model of all variables | Model after Backward Elimination | |||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
OR | 95% CI for OR | p | OR | 95% CI for OR | p | OR | 95% CI for OR | p | ||||
Lower | Upper | Lower | Upper | Lower | Upper | |||||||
Grade | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â |
1 | 1 | reference | Â | Â | 1 | reference | Â | Â | 1 | reference | Â | Â |
2 | 1.04 | 0.88 | 1.23 | 0.635 | 0.99 | 0.84 | 1.17 | 0.907 | 0.99 | 0.84 | 1.18 | 0.927 |
3 | 0.85 | 0.73 | 1.01 | 0.062 | 0.79 | 0.66 | 0.93 | 0.005 | 0.79 | 0.67 | 0.93 | 0.006 |
4 | 0.85 | 0.72 | 1 | 0.053 | 0.74 | 0.62 | 0.89 | 0.001 | 0.75 | 0.63 | 0.89 | 0.001 |
5 | 0.81 | 0.68 | 0.96 | 0.013 | 0.66 | 0.55 | 0.79 | < 0.001 | 0.66 | 0.55 | 0.79 | < 0.001 |
6 | 0.76 | 0.64 | 0.89 | 0.001 | 0.58 | 0.48 | 0.7 | < 0.001 | 0.58 | 0.48 | 0.69 | < 0.001 |
Sex | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â |
boy | 1 | reference | Â | Â | 1 | reference | Â | Â | 1 | reference | Â | Â |
girl | 1.15 | 1.04 | 1.27 | 0.005 | 1.21 | 1.1 | 1.34 | < 0.001 | 1.21 | 1.09 | 1.33 | < 0.001 |
Weekday sleep duration, hours | 0.91 | 0.86 | 0.97 | 0.004 | 0.82 | 0.75 | 0.88 | < 0.001 | 0.82 | 0.76 | 0.89 | < 0.001 |
Weekend sleep duration, hours | 1.07 | 1.01 | 1.13 | 0.023 | 1.17 | 1.09 | 1.25 | < 0.001 | 1.16 | 1.09 | 1.25 | < 0.001 |
Have their own digital device | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â |
No | 1 | reference | Â | Â | 1 | reference | Â | Â | 1 | reference | Â | Â |
Yes | 1.13 | 1.03 | 1.25 | 0.012 | 1.13 | 1.01 | 1.27 | 0.034 | 1.11 | 1 | 1.23 | 0.058 |
Constantly checking his/her digital device | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â |
No | 1 | reference | Â | Â | 1 | reference | Â | Â | Â | Â | Â | Â |
Yes | 1.19 | 1.05 | 1.35 | 0.007 | 0.91 | 0.78 | 1.07 | 0.248 | Â | Â | Â | Â |
Using digital devices for more than 4 hours a day |  |  |  |  |  |  |  |  |  |  |  |  |
No/Unknown | 1 | reference | Â | Â | 1 | reference | Â | Â | Â | Â | Â | Â |
Yes | 1.26 | 1.08 | 1.48 | 0.004 | 0.94 | 0.78 | 1.13 | 0.515 | Â | Â | Â | Â |
Do you think your child is preoccupied with the Internet? | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â |
No/Unknown | 1 | reference | Â | Â | 1 | reference | Â | Â | Â | Â | Â | Â |
Yes | 1.46 | 1.33 | 1.61 | < 0.001 | 1.12 | 0.98 | 1.27 | 0.092 |  |  |  |  |
Do you think your child needs to use the Internet with increasing amounts of time in order to achieve satisfaction? | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â |
No/Unknown | 1 | reference | Â | Â | 1 | reference | Â | Â | Â | Â | Â | Â |
Yes | 1.4 | 1.27 | 1.54 | < 0.001 | 0.98 | 0.86 | 1.13 | 0.816 |  |  |  |  |
Do you think your child repeatedly makes unsuccessful efforts to control, cut back, or stop Internet use? | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â |
No/Unknown | 1 | reference | Â | Â | 1 | reference | Â | Â | 1 | reference | Â | Â |
Yes | 1.58 | 1.42 | 1.76 | < 0.001 | 1.13 | 0.98 | 1.31 | 0.097 | 1.15 | 1 | 1.32 | 0.058 |
Do you think your child feels restless, moody, depressed, or irritable when attempting to cut down or stop Internet use? | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â |
No/Unknown | 1 | reference | Â | Â | 1 | reference | Â | Â | 1 | reference | Â | Â |
Yes | 1.74 | 1.55 | 1.95 | < 0.001 | 1.43 | 1.24 | 1.65 | < 0.001 | 1.48 | 1.29 | 1.7 | < 0.001 |
Do you think your child stays on-line longer than originally intended? | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â |
No/Unknown | 1 | reference | Â | Â | 1 | reference | Â | Â | 1 | reference | Â | Â |
Yes | 1.54 | 1.4 | 1.71 | < 0.001 | 1.24 | 1.08 | 1.42 | 0.002 | 1.27 | 1.12 | 1.44 | < 0.001 |
Do you think your child jeopardized or risked the loss of a significant relationship, educational, or extracurricular activities because of the Internet? | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â |
No/Unknown | 1 | reference | Â | Â | 1 | reference | Â | Â | Â | Â | Â | Â |
Yes | 1.77 | 1.29 | 2.42 | < 0.001 | 1.2 | 0.86 | 1.68 | 0.278 |  |  |  |  |
Do you think your child lied to family members, a therapist, or others to conceal the extent of involvement with the Internet? | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â |
No/Unknown | 1 | reference | Â | Â | 1 | reference | Â | Â | Â | Â | Â | Â |
Yes | 1.46 | 1.23 | 1.72 | < 0.001 | 1.09 | 0.9 | 1.31 | 0.368 |  |  |  |  |
Do you think your child uses the Internet as a way of escaping from problems or relieving a dysphoric mood? | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â |
No/Unknown | 1 | reference | Â | Â | 1 | reference | Â | Â | 1 | reference | Â | Â |
Yes | 1.66 | 1.34 | 2.08 | < 0.001 | 1.26 | 0.99 | 1.6 | 0.059 | 1.3 | 1.03 | 1.64 | 0.027 |