Characteristics of study population
|
Asthma cases (n = 1380) |
Respiratory cases (n = 2131) |
Controls (n = 5703) | |
| Mean (SD) age (years) | 8.4 (2.8) | 8.4 (2.9) | 9.5 (2.9) |
| Percent male | 63.3% | 60.4% | 55.9% |
| Median Carstairs deprivation score (IQ range) | 0.25 (−1.64 to 2.29) | 0.19 (−1.66 to 2.16) | 0.03 (−1.84 to 1.95) |
| Distance in metres from major road (%) | |||
| 0–74 | 16.6% | 16.9% | 16.5% |
| 75–149 | 21.2% | 22.9% | 22.8% |
| 150–299 | 28.5% | 26.9% | 27.2% |
| 300+ | 33.7% | 33.3% | 33.5% |
| Median distance from main road (IQ range) | 201.8 (105.1 to 370.7) | 195.9 (100.1 to 373.9) | 196.2 (102.6 to 378.5) |
| Traffic volume within 150 m (vehicle-metres/h) | |||
| <1500 | 28.7% | 28.8% | 27.5% |
| 1500–14 999 | 25.7% | 24.0% | 23.4% |
| 15 000–49 999 | 24.3% | 24.7% | 27.3% |
| 50 000+ | 21.2% | 22.5% | 21.8% |