Table 1.
Summary of register, ecological, MCS data, and MCS data weighted to represent the population. Continuous variables summarized as mean (standard deviation), discrete variables summarized as number and percentage
| Administrative data | Millennum Cohort | Millennium Cohort (weighted) | |
| Register data | |||
| Number of births | 56 525 | 13 143 | 13 143 |
| Birth weight (kg) | 3.36 (0.58) | 3.33 (0.58) | 3.37 (0.57) |
| Low birth weight (< 2.5 kg†) | 3474 (6.1%) | 900 (6.8%) | 793 (6%) |
| NO2 | 29.41 (8.54) | 29.19 (8.98) | 28.66 (8.25) |
| SO2 | 04.2 (1.87) | 4.13 (1.7) | 4.17 (1.7) |
| Social class | |||
| Professional | 1877 (3.3%) | 332 (2.5%) | 452 (3.4%) |
| Managerial, technical | 12 975 (23%) | 2683 (20.4%) | 3258 (24.8%) |
| Skilled nonmanual | 12 062 (21.3%) | 4104 (31.2%) | 4363 (33.2%) |
| Skilled manual | 2875 (5.1%) | 1111 (8.5%) | 1168 (8.9%) |
| Partly skilled | 4422 (7.8%) | 2589 (19.7%) | 2329 (17.7%) |
| Unskilled | 539 (1%) | 495 (3.8%) | 460 (3.5%) |
| Other | 21 775 (38.5%) | 1759 (13.4%) | 1062 (8.1%) |
| Aggregate data | |||
| Inactive‡ | 21 573 (38.2%) | 7224 (55%) | 6480 (49.3%) |
| Ethnic group | |||
| White | 88.3% | 10 342 (78.7%) | 11 484 (87.4%) |
| South Asian | 5.7% | 1658 (12.6%) | 870 (6.6%) |
| Black | 2.9% | 616 (4.7%) | 380 (2.9%) |
| Other | 3.1% | 489 (3.7%) | 372 (2.8%) |
| Tobacco§ | 237 (85) | ||
| Smoking¶ | 4036 (30.7%) | 3931 (29.9%) | |
†
The standard definition (United Nations Children's Fund and World Health Organization, 2004).
‡
Unemployed or economically inactive.
§
Annual tobacco expenditure per person (pounds).
¶
Smoking during pregnancy.