Demographic characteristics of the 14908 children included in the analyses stratified by sample
| White representative (n=9507) | Inner city England (n=5401) | |
| Sex | ||
| Boys | 4845 (51.0%) | 2698 (50.0%) |
| Girls | 4662 (49.0%) | 2703 (50.0%) |
| No of children per household | ||
| 1 | 840 (8.8%) | 460 (8.5%) |
| 2 | 4182 (44.0%) | 1290 (23.9%) |
| 3 | 2495 (26.2%) | 1122 (20.8%) |
| 4 | 956 (10.0%) | 841 (15.6%) |
| ⩾5 | 637 (4.2%) | 1159 (21.4%) |
| NK | 397 (4.2%) | 529 (9.8%) |
| Social class | ||
| Non-manual | 2819 (29.7%) | 664 (12.3%) |
| Skilled manual | 2921 (30.6%) | 1099 (20.4%) |
| Semi & unskilled | 1323 (13.9%) | 872 (16.1%) |
| One parent family (mother) | 1792 (18.9%) | 1630 (30.2%) |
| NK | 661 (6.9%) | 1136 (21.0%) |
| Ethnicity | ||
| White | 9507 (100.0%) | 1784 (33.0%) |
| Afro-Caribbean | – | 881 (16.3%) |
| Urdu | – | 366 (6.8%) |
| Gujarati | – | 335 (6.2%) |
| Punjabi | – | 978 (18.0%) |
| Other Asian | – | 437 (8.1%) |
| Other | – | 558 (10.3%) |
| Unknown | – | 62 (1.1%) |
NK = not known.