Table 2.
Relative risk ratios (RRR) for transient and persistent asthma compared with never by SEC adjusted for blocks of mediators (N=7487)
| Baseline model | Model 1 | Model 2 | Model 3 | Model 4 | ||||||
| RRR* | 95% CI | RRR | 95% CI | RRR | 95% CI | RRR | 95% CI | RRR | 95% CI | |
| Transient asthma | ||||||||||
| Diploma | 0.86 | 0.62 to 1.19 | 0.81 | 0.58 to 1.12 | 0.81 | 0.58 to 1.12 | 0.79 | 0.56 to 1.10 | 0.78 | 0.55 to 1.09 |
| A levels | 0.93 | 0.65 to 1.34 | 0.83 | 0.57 to 1.21 | 0.82 | 0.57 to 1.19 | 0.79 | 0.54 to 1.15 | 0.76 | 0.52 to 1.12 |
| GCSE A–C | 1.01 | 0.69 to 1.47 | 0.87 | 0.59 to 1.27 | 0.85 | 0.57 to 1.26 | 0.81 | 0.55 to 1.20 | 0.77 | 0.52 to 1.15 |
| GCSE D–G | 1.26 | 0.74 to 2.14 | 1.09 | 0.65 to 1.85 | 1.08 | 0.64 to 1.83 | 1.03 | 0.61 to 1.74 | 0.96 | 0.57 to 1.63 |
| None | 0.92 | 0.56 to 1.51 | 0.73 | 0.44 to 1.23 | 0.71 | 0.42 to 1.21 | 0.68 | 0.40 to 1.15 | 0.63 | 0.38 to 1.05 |
| Persistent asthma | ||||||||||
| Diploma | 1.03 | 0.78 to 1.36 | 0.96 | 0.72 to 1.27 | 0.96 | 0.73 to 1.27 | 0.95 | 0.72 to 1.26 | 0.95 | 0.72 to 1.26 |
| A levels | 1.08 | 0.78 to 1.50 | 0.96 | 0.69 to 1.35 | 0.97 | 0.69 to 1.36 | 0.96 | 0.68 to 1.35 | 0.95 | 0.67 to 1.33 |
| GCSE A–C | 1.24 | 0.91 to 1.70 | 1.09 | 0.79 to 1.51 | 1.10 | 0.80 to 1.52 | 1.10 | 0.79 to 1.53 | 1.08 | 0.78 to 1.49 |
| GCSE D–G | 1.50 | 0.95 to 2.35 | 1.34 | 0.85 to 2.12 | 1.35 | 0.86 to 2.13 | 1.36 | 0.85 to 2.15 | 1.31 | 0.83 to 2.07 |
| None | 1.71 | 1.07 to 2.74 | 1.35 | 0.86 to 2.12 | 1.35 | 0.86 to 2.10 | 1.37 | 0.87 to 2.16 | 1.31 | 0.82 to 2.09 |
| Proportion attenuated (%)† | ||||||||||
| 50.70 | 50.70 | 47.89 | 56.34 | |||||||
Model 1: Baseline model+perinatal characteristics (maternal pre-pregnancy body mass index; breastfeeding duration; birth weight; gestation; maternal smoking during pregnancy; alcohol use during pregnancy; wheeze.
Model 2: Model 1+housing conditions (damp; tenure; furry pets; environmental tobacco smoke; access to garden).
Model 3: Model 2+potential exposure to infection (sibling number; childcare type).
Model 4: Model 3+neighbourhood characteristics (volume of traffic; housing quality; rubbish; area rating).
*All models were adjusted for baseline confounders (child sex, maternal age at birth, maternal ethnicity and maternal atopy). Degree plus is the reference category.
†Proportion of RRR of persistent asthma attenuated by comparison of baseline model with models 1–4 for lowest SECs (100×(RRR-adjusted RRR)/(RRR-1))
GCSE, General Certificate of Secondary Education; SEC, socioeconomic circumstances.