Characteristics of cases and controls
| Cases | Controls | p Value | |
|---|---|---|---|
| *Atopy defined by at least one positive (2 mm or greater than saline response) skin test to allergens tested. | |||
| †Higher Carstairs index denotes greater social deprivation. | |||
| Sex | |||
| Boys | 107 (55%) | 113 (51%) | |
| Girls | 86 (45%) | 110 (49%) | 0.33 |
| Age (years) | |||
| 9 | 68 (35%) | 83 (37%) | |
| 10 | 73 (38%) | 72 (32%) | |
| 11 | 52 (27%) | 68 (31%) | 0.48 |
| Years lived in home | |||
| <3 years | 30 (16%) | 38 (17%) | |
| ⩾3 years | 162 (84%) | 183 (82%) | |
| Missing | 1 (0.5%) | 2 (1%) | 0.82 |
| Atopic* | |||
| Yes | 132 (68%) | 57 (26%) | |
| No | 60 (31%) | 161 (72%) | |
| Missing | 1 (0.5%) | 5 (2%) | <0.001 |
| Carstairs index based on current residence† (mean (SD)) | 0.87 (3.90) | 0.17 (3.40) | 0.055 |