Table 5. The association between the duration of screen exposure during the evening and at night on sleep and daytime function adjusted for age, sex and sociodemographic class adjusted for screen possession and presence of a screen in the bedroom (adjusted OR only).
| Evening screen exposure compared to students using screens for <1 hour* | Night time screen exposure compared to students not using screens at night ** | |||||
|---|---|---|---|---|---|---|
| 1–2 hours screen use N = 641 | >2 hours screen use N = 549 | 30 minutes N = 327 | 30–60 minutes N = 154 | 60–120 minutes N = 82 | >120 minutes N = 86 | |
| Adjusted OR [IC95%] | Adjusted OR [IC95%] | Adjusted OR [IC95%] | Adjusted OR [IC95%] | Adjusted OR [IC95%] | Adjusted OR [IC95%] | |
| Sleep deprivation on schooldays | 0.87(0.649 1.17) | 2.62 (2.01–3.42) | 2.21 (1.61–3.03) | 3.07 (2.02–4.66) | 5.93 (3.44–10.21) | 7.79 (4.48–13.52) |
| Sleep restriction | 1,22 (0.99–1.52) | 1.60 (1.27–2.02) | 1.61 (1.23–2.11) | 1.80 (1.23–2.64) | 2.90 (1.72–4.91) | 1.93 (1.15–3.24) |
| Insomnia | 0.84 (0.63–1.12) | 1.63 (1.25–2.12) | 2.42 (1.78–3.29) | 2.92 (1.97–4.32) | 4.48 (2.75–7.29) | 5.62 (3.44–9.17) |
| Lack of energy | 1.62 (0.94–1.43) | 1.48 (1.19–1.84) | 1.54 (1.19–1.99) | 2.10 (1.49–2.98) | 3.98 (2.42–6.56) | 2.70 (1.66–4.40) |
| Irritability | 1.11 (0.86–1.43) | 1.65 (1.28–2.12) | 1.69 (1.27–2.27) | 2.69 (1.87–3.88) | 1.65 (0.97–2.80) | 3.56 (2.19–5.80) |
| Daytime sleepiness | 1.32 (1.07–1.62) | 2.11 (1.69–2.63) | 1.63 (1.27–2.11) | 2.49 (1.75–3.54) | 3.79 (2.31–6.22) | 3.05 (1.86–5.00) |
| Poor quality sleep | 1.25 (1.01–1.53) | 1.61 (1.29–2.00) | 1.73 (1.34–2.23) | 2.36 (1.65–3.37) | 3.02 (1.86–4.92) | 2.14 (1.32–3.48) |
Significant data (p < 0.0001) are shown in bold
* Adolescent who use screens for more than 1 hour are compared with those who have an evening screen exposure of less than 1 hour considered as the reference class (N = 1323, OR = 1)
**Adolescent who have a nighttime screen exposure are compared with those who never use screen during the night considered a the reference class (N = 1841, OR = 1)
OR ratio are adjusted for age, gender and geographic area of the school as a proxy of socio economic level screen possession and presence of a screen in the bedroom