Table 1 Characteristics of the two control groups and the cases.
| Cases/294 | Control group 1/294 | Control group 2/294 | |
|---|---|---|---|
| Mean age (SD) | 34.2 (13.3) | 34.2 (13.3) | 34.2 (13.3) |
| Men/women | 78/216 | 78/216 | 78/216 |
| Quintile 1 (least deprived) n (%) | 74 (25.2) | 113 (38.4) | 94 (32.0) |
| Quintile 2 n (%) | 136 (46.2) | 152 (51.7) | 145 (49.3) |
| Quintile 3 n (%) | 8 (2.7) | 5 (1.7) | 8 (2.7) |
| Quintile 4 n (%) | 55 (18.7) | 21 (7.1) | 32 (10.9) |
| Quintile 5 (most deprived) n (%) | 21 (7.1) | 3 (1.0) | 15 (5.1) |
| Mean index of deprivation score (SD) | 15.2 (9.9) | 10.7 (6.6) | 12.9 (8.7) |