Table 3.
Description of the study population (N=1270)
| Non-imputed values | Imputed values | ||
|---|---|---|---|
| Covariate | n (SD) | Missing (n) | n (SD) |
| Child’s age yrs (IQR) | 8.0 (2.4) | 0 | 8.0 (2.4) |
| n (%) | n (%) | ||
| Gender | 0 | ||
| Female | 571 (45) | 571 (45) | |
| Child’s ethnicity a | 27 | ||
| No native parents | 136 (11) | 142 (11) | |
| Only one native parent | 63 (5) | 66 (5) | |
| Both parents native | 1044 (84) | 1062 (84) | |
| Parity | 30 | ||
| No child | 568 (45) | 579 (46) | |
| 1 child | 447 (35) | 458 (36) | |
| ≥2 children | 225 (18) | 233 (18) | |
| Season of conception | 13 | ||
| Jan-March | 401 (32) | 407 (32) | |
| April-June | 253 (20) | 255 (20) | |
| July-Sept | 274 (22) | 277 (22) | |
| Oct-Dec | 329 (26) | 331 (26) | |
| Nursery attendance | 26 | ||
| Yes | 515 (41) | 734 (58) | |
| Pre-pregnancy maternal BMI | 23 | ||
| <18.5 | 49 (4) | 49 (4) | |
| 18.5–24.9 | 711 (56) | 724 (57) | |
| 25–29.9 | 305 (24) | 309 (24) | |
| ≥30 | 182 (14) | 188 (15) | |
| Maternal education b | 43 | ||
| Low | 170 (13) | 180 (14) | |
| Middle | 427 (34) | 437 (34) | |
| High | 630 (50) | 653 (51) | |
| Paternal education b | 87 | ||
| Low | 207 (16) | 236 (19) | |
| Middle | 465 (37) | 486 (38) | |
| High | 511 (40) | 548 (43) | |
a
defined as the parents’ country of birth (country of the cohort or not)
b
Low education:primary school; low education: secondary school; high education: university degree or higher