Table 1.
Sample characteristics by early biological risk
| Not at risk n = 1704 | At risk n = 196 | p* | |
|---|---|---|---|
| Country (%) | |||
| UK | 40.3 | 49.5 | |
| Netherlands | 30.2 | 22.4 | |
| Spain | 29.6 | 28.1 | .026 |
| Gender (%) | |||
| Male | 48.2 | 38.3 | |
| Female | 51.8 | 61.7 | .008 |
| Age in days | |||
| Mean (SD) | 3844.5 (180.4) | 3858.8 (192.5) | .298 |
| Employment status (%) | |||
| Unemployed | 13.0 | 20.9 | |
| Employed | 87.0 | 79.1 | .002 |
| Crowding at (%) | |||
| Not crowded | 79.5 | 83.7 | |
| Crowded | 20.5 | 16.3 | .169 |
| Home ownership (%) | |||
| Not owned | 24.6 | 31.6 | |
| Owned | 75.4 | 68.4 | .032 |
| Mother's educational achievement | |||
| Mean (SD) | 0.49 (0.28) | 0.51 (0.30) | .260 |
| Long-standing illness (%) | |||
| No | 76.0 | 73.0 | |
| Yes | 24.0 | 27.0 | .348 |
| Main language spoken at home (%) | |||
| No | 8.7 | 10.7 | |
| Yes | 91.3 | 89.3 | .345 |
| Parental support scale | |||
| Mean (SD) | 10.0 (2.0) | 10.3 (1.8) | .129 |
| Classroom glazing type (%) | |||
| Single | 50.4 | 55.6 | |
| Double (or both single and double) | 46.4 | 44.4 | |
| Triple | 3.2 | 0.0 | .024 |
*p represents significance value for χ2 test or t-test depending on nature of data.