| Categorical variable | Age when measured | Category | N (%) | |
| Smoking | 53 | Never | 384 (49) | |
| Ex | 239 (30) | |||
| Current | 167 (21) | |||
| Childhood SEP | 53 | Professional | 57 (7) | |
| Intermediate | 160 (21) | |||
| Skilled (non-manual) | 123 (16) | |||
| Skilled (manual) | 245 (31) | |||
| Partly skilled | 148 (19) | |||
| Unskilled | 48 (6) | |||
| Adult SEP | 53 | Professional | 14 (2) | |
| Intermediate | 261 (33) | |||
| Skilled (non-manual) | 286 (36) | |||
| Skilled (manual) | 57 (7) | |||
| Partly skilled | 119 (15) | |||
| Unskilled | 50 (7) | |||
| Education | 53 | None | 275 (35) | |
| Vocational | 44 (5) | |||
| Sub-GCE | 38 (5) | |||
| O level | 201 (26) | |||
| A level | 106 (14) | |||
| Burham A2 | 75 (10) | |||
| Degree | 32 (4) | |||
| Postgraduate | 2 (1) | |||
BMI, body mass index; GCE, General Certificate of Education; SEP, socioeconomic position.