Characteristics of children (1–16 years)* in Norway, 2008–2016
| Number of children (% admitted) | 1 538 189 | (10.15) |
| Child’s age, mean (SD) | 6.16 | (5.19) |
| Boys, n (%) | 789 635 | (51.34) |
| Mother’s age, mean (SD) | 35.81 | (6.83) |
| Missing, n (%) | 7643 | (0.50) |
| Father’s age, mean (SD) | 38.87 | (7.59) |
| Missing, n (%) | 39 457 | (2.57) |
| Mother’s education ISCED, mean (SD) | 4.7 | (1.73) |
| Father’s education ISCED, mean (SD) | 4.48 | (1.70) |
| Mother’s educational level, categorical | ||
| Low, n (%) | 261 226 | (16.98) |
| Medium, n (%) | 488 739 | (31.77) |
| High, n (%) | 703 200 | (45.72) |
| Missing, n (%) | 85 024 | (5.53) |
| Father’s educational level, categorical | ||
| Low, n (%) | 267 667 | (17.40) |
| Medium, n (%) | 644 727 | (41.91) |
| High, n (%) | 515 724 | (33.53) |
| Missing, n (%) | 110 071 | (7.16) |
| No of siblings, mean (SD) | 1.53 | (1.27) |
| Missing, n (%) | 4 697 | (0.31) |
| Only child, n (%) | 282 498 | (18.37) |
*Based on the start of the follow-up for each child.
ISCED, international standard of classification of education.