Table 1.
Participants’ Sociodemographic Characteristics (N = 7918)
| Sociodemographic characteristics | Sample | |
|---|---|---|
| n | % | |
| Gender | ||
| Male | 3697 | 46.7 |
| Female | 4218 | 53.3 |
| Age groups | ||
| 13 years | 1185 | 15 |
| 14 years | 1403 | 17.7 |
| 15 years | 1713 | 21.6 |
| 16 years | 1385 | 17.5 |
| 17 years | 1103 | 13.9 |
| ≥18 years | 1129 | 14.3 |
| School yeara | ||
| 6th grade (11 years old) | 48 | 0.6 |
| 7th grade (12 years old) | 1752 | 22.1 |
| 8th grade (13 years old) | 1673 | 21.1 |
| 9th grade (14 years old) | 1975 | 24.9 |
| 10th grade (15 years old) | 1122 | 14.2 |
| 11th grade (16 years old) | 780 | 9.9 |
| 12th grade (17 years old) | 568 | 7.2 |
| Ever failed a school year | ||
| Yes | 2593 | 35.4 |
| No | 5734 | 64.6 |
aThe ages most commonly associated with each Portuguese school year are presented in parentheses