Table 2.
Magnitude of effect of main effect on asthma aetiology and magnitude of interaction with other factor
| Study | Interaction between | Magnitude of interaction (95% CI) |
|---|---|---|
| Robison et al16 | Late premature delivery (<37 weeks) and antenatal SHS exposure | OR for wheeze 2.0 (1.3 to 3.1) associated with prematurity and 1.1 (0.5 to 2.4) with in utero SHS exposure. OR for wheeze 3.8 (1.8 to 8.0) if both premature and SHS exposed |
| Martinez et al19 | Smoke exposure from mother | OR 2.6 (1.4 to 4.6) if exposed and mother ≤12 years education OR 1.7 (1.1 to 2.6) for asthma by 5 years |
| Diez et al27 | Redecoration Pet exposure Dampness |
Redecoration associated with OR for obstructive bronchiolitis at 2 years 4.1 (1.4 to 12.9). OR 5.1 (1.6 to 15.6) if also exposed to ETS or pets |
| Jung et al35 | Pyrene exposure Atopy |
High exposure was associated with increased risk for asthma 1.9 (1.1 to 3.2) and this was increased to 2.9 (1.8 to 5.7) among non-atopic children |
| Carlsten et al56 | Dog exposure SHS High NO2 |
No association with dog exposure per se OR 2.7 (1.1 to 7.1) for dog and SHS OR 4.8 (1.1 to 21.5) for dog plus high NO2 |
| Karmus et al57 | Recurrent lower respiratory tract infection Breast feeding SHS |
OR 2.5 (1.8 to 3.4) for asthma at ages 4 and 10 years. OR 3.1 (1.8 to 5.2) with antenatal exposure to products of tobacco smoke |
| Melen et al61 | Smoke exposure Pets Window pane condensation |
OR for 1 to 2 and 3 exposures (compared to none) were 1.1, 4.4 (1.0 to 18.6) and 10.8 (2.0 to 59.6) |
| Celedon et al62 | Early cat exposure Maternal asthma |
Exposure associated with reduced risk for wheeze (OR 0.6 (0.4 to 0.9)) but only in those with no maternal asthma |
| Trevillian et al71 | Synthetic bedding Bedroom heating Recent bedroom painting |
Exposure to >1 synthetic item of bedding was associated with increased asthma (OR 1.8 (1.0 to 3.2)). Co-exposure to room heating was associated with OR 7.1 (0.1 to 23.9), recent painting OR 7.2 (2.3 to 23.2) |
| Kim et al81 | Ambient air pollution (ozone, CO, NO2, SO2 and PM10) Previous bronchiolitis |
Asthma at 5 years not associated with higher exposures but among bronchiolitis subset ozone exposure associated with OR 7.5 (2.7 to 21.3), CO exposure OR 8.3 (2.9 to 23.7) and NO2 exposure OR 7.9 (0.97 to 64.8) |
| Ryan et al82 | Traffic-related particles (elemental carbon attributable to traffic) Domestic LPS |
A positive asthma predictive index at 36 months was associated with exposure to increased levels of particles before 12 months (OR=2.0 (1.2 to 3.6)). Co-exposure to high concentrations of endotoxin increased the risk (OR=3.4 (1.3 to 8.9)) |
| Kusel et al129 | Atopy Virus positive wheezing illness |
OR 3.1 (1.5 to 6.4) if atopic for wheeze at 5 years. OR 3.9 (1.4 to 10.5) if also wheezy illness |
LPS, lipopolysaccharide; SHS, secondhand smoke.