Baseline characteristics* of the sample at wave 1 by cohort
| Demographic variable | Total sample | Included in all trajectories? | ||||
| Yes | No | |||||
| B (0–1 y) (n=4569–5107) | K (4–5 y) (n=4237–4983) | B (0–1 y) (n=4050–4443) | K (4–5 y) (n=3969–4620) | B (0–1 y) (n=520–664) | K (4–5 y) (n=268–363) | |
| Child age (y), mean (SD) | 0.7 (0.2) | 4.8 (0.2) | 0.7 (0.2) | 4.8 (0.2) | 0.7 (0.2) | 4.8 (0.2) |
| Child sex, % male | 51.1 | 51.2 | 51.3 | 51.5 | 50.1 | 48.1 |
| Indigenous status, % indigenous | 4.9 | 3.9 | 4.0 | 3.6 | 10.7 | 7.4 |
| Child language other than English spoken at home, % English only | 88.9 | 87.6 | 90.2 | 88.2 | 80.0 | 79.3 |
| Parent 1 age (y), mean (SD) | 31.0 (5.7) | 34.6 (5.5) | 31.3 (5.5) | 34.7 (5.5) | 29.1 (6.5) | 33.3 (6.3) |
| Parent 2 age (y), mean (SD) | 33.8 (6.1) | 37.4 (6.2) | 34.0 (6.0) | 37.4 (6.1) | 32.2 (6.7) | 36.8 (0†) |
| Number of older siblings, % | ||||||
| 0 | 40.8 | 41.2 | 41.0 | 41.2 | 40.1 | 41.4 |
| 1 | 35.7 | 34.9 | 36.2 | 35.1 | 32.8 | 32.6 |
| 2 | 15.8 | 16.1 | 15.7 | 16.2 | 16.9 | 14.5 |
| 3+ | 7.6 | 7.8 | 7.2 | 7.5 | 10.2 | 11.5 |
| Child, % single birth | 96.9 | 97.2 | 96.7 | 97.2 | 98.2 | 96.9 |
| Either parent highest education, % | ||||||
| Degree | 37.5 | 33.9 | 39.8 | 34.9 | 22.3 | 20.6 |
| Completed school | 33.7 | 29.7 | 33.9 | 29.9 | 32.2 | 27.1 |
| Did not complete school | 28.9 | 36.5 | 26.4 | 35.2 | 45.5 | 52.3 |
| Neighbourhood disadvantage, % | ||||||
| Quintile 1 (least disadvantaged) | 19.2 | 18.1 | 19.8 | 18.4 | 15.1 | 13.9 |
| Quintile 2 | 17.0 | 18.0 | 17.4 | 18.0 | 14.2 | 17.9 |
| Quintile 3 | 20.3 | 19.8 | 20.1 | 19.8 | 21.4 | 20.1 |
| Quintile 4 | 21.0 | 20.7 | 20.8 | 20.9 | 22.3 | 17.2 |
| Quintile 5 (most disadvantaged) | 22.6 | 23.4 | 21.9 | 22.8 | 27.0 | 31.0 |
| SEP, % | ||||||
| Quintile 1 (highest SEP) | 20.0 | 20.0 | 21.5 | 20.8 | 10.1 | 9.0 |
| Quintile 2 | 20.0 | 20.0 | 21.3 | 20.6 | 11.4 | 12.6 |
| Quintile 3 | 20.0 | 20.0 | 20.5 | 20.2 | 16.8 | 17.6 |
| Quintile 4 | 20.0 | 20.0 | 19.7 | 19.5 | 21.9 | 26.7 |
| Quintile 5 (lowest SEP) | 20.0 | 20.0 | 17.1 | 18.9 | 39.8 | 34.1 |
| Combined yearly income pretax, % | ||||||
| <$26 000/year | 14.2 | 12.7 | 12.0 | 11.5 | 29.1 | 28.0 |
| $26 000–$51 999/year | 33.6 | 31.5 | 32.7 | 31.0 | 40.0 | 37.7 |
| $52 000–$103 999/year | 39.4 | 41.1 | 41.7 | 42.3 | 23.3 | 25.3 |
| $104 000+/year | 12.8 | 14.7 | 13.6 | 15.2 | 7.5 | 8.9 |
| Parents’ mean hours work/week, % | ||||||
| 0 | 13.8 | 13.7 | 11.3 | 12.6 | 30.6 | 27.8 |
| 1–39 | 13.0 | 13.3 | 12.3 | 13.0 | 17.2 | 16.8 |
| 40–59 | 36.8 | 32.0 | 38.1 | 32.4 | 28.1 | 26.7 |
| 60–79 | 23.8 | 26.1 | 25.0 | 26.7 | 15.8 | 18.5 |
| 80+ | 12.7 | 14.9 | 13.4 | 15.3 | 8.3 | 10.2 |
| Remoteness area, % | ||||||
| Major cities | 69.4 | 67.4 | 68.8 | 67.1 | 73.2 | 70.8 |
| Inner regional | 17.9 | 18.8 | 18.5 | 19.0 | 13.9 | 15.8 |
| Outer regional, remote or very remote | 12.7 | 13.8 | 12.7 | 13.9 | 12.9 | 13.4 |
| Home ownership, % | ||||||
| Owned outright | 6.9 | 10.6 | 7.2 | 10.8 | 5.0 | 8.5 |
| Being paid off | 55.4 | 57.3 | 58.2 | 58.8 | 36.4 | 38.3 |
| Rented | 30.8 | 28.3 | 28.0 | 26.8 | 49.7 | 48.1 |
| Other | 6.9 | 3.7 | 6.6 | 3.6 | 8.9 | 5.1 |
| Financial limits buying food, % yes | 37.6 | 38.1 | 36.1 | 37.2 | 47.7 | 49.4 |
*All estimates are weighted.
†Missing SE because of stratum with single sampling unit.
B, Baby Cohort; K, Kindergarten Cohort; SEP, socioeconomic position; y, years.