Table 1. Sociodemographic data of the participants (n = 373).
SD: standard deviation
| Variable | Categories | N (%) |
| Age (in years) | Mean ± SD | 15.8 ± 5.56 |
| Average no. of hours/day spent on mobile phones | Mean ± SD | 6.9 ± 4.45 |
| Gender | Male | 246 (66) |
| Female | 127 (34) | |
| Educational level | 1st year | 119 (31.9) |
| 2nd year | 153 (41) | |
| 3rd year | 101 (27.1) | |
| School type | Government | 324 (86.9) |
| Private | 43 (11.5) | |
| Other | 6 (1.6) | |
| Educational path | Common first year | 13 (3.5) |
| General | 304 (81.5) | |
| Computer science and engineering | 10 (2.7) | |
| Health and life | 9 (2.4) | |
| Course system | 23 (6.2) | |
| Literary | 6 (1.6) | |
| Scientific | 8 (2.1) | |
| Marital status | Single | 366 (98.1) |
| Married | 7 (1.9) | |
| Living place | With parents | 319 (85.5) |
| With one of the parents | 43 (11.5) | |
| Other | 11 (2.9) | |
| Monthly family income (in Saudi riyal (SAR)) | <5,000 | 179 (48) |
| 5,000-10,000 | 96 (25.7) | |
| >10,000 | 98 (26.3) | |
| Chronic disease | Yes | 65 (17.4) |
| No | 308 (82.6) | |
| Having caffeine less than six hours before bedtime | Yes | 178 (47.7) |
| No | 195 (52.3) | |
| Regular sports activity | Yes | 105 (28.2) |
| No | 268 (71.8) |