Table 2.
Associations of selected allergic and respiratory outcomes at age 5 years in relation to weighted road density within a 50 m radius of home adjusted for potential confounders stratified by fish oil supplementation
| Total IgE | No fish oil supplementation | Fish oil supplementation | p-value for interaction | ||||||
|---|---|---|---|---|---|---|---|---|---|
| N | Mean difference | 95% CI | p-value | N | Mean difference | 95% CI | p-value | ||
| Total IgE (kU/L) | 165 | −0.023 | −0.29−0.34 | 0.760 | 161 | −0.18 | −0.34−0.20 | 0.785 | 0.291 |
| Questionnaire variables | RR | RR | |||||||
| Doctor diagnosed asthma | 186 | 0.91 | 0.58–1.43 | 0.689 | 186 | 1.18 | 0.82–1.71 | 0.370 | 0.384 |
| Ever had doctor diagnosed asthma | 186 | 0.91 | 0.63–1.29 | 0.556 | 186 | 1.10 | 0.84–1.44 | 0.746 | 0.423 |
| Wheeze in the last 12 months | 186 | 1.18 | 0.81–1.72 | 0.387 | 186 | 1.05 | 0.79–1.39 | 0.724 | 0.664 |
| Wheeze in the last 12 months & asthma | 186 | 1.08 | 0.60–1.95 | 0.798 | 186 | 0.90 | 0.59–1.38 | 0.641 | 0.770 |
| Cough more than 4 times in the last 12 months | 186 | 1.14 | 0.81–1.59 | 0.459 | 186 | 1.20 | 0.95–1.53 | 0.132 | 0.794 |
| Doctor diagnosed Eczema | 186 | 1.13 | 0.78–1.65 | 0.514 | 186 | 1.43 | 1.10–1.87 | 0.007 | 0.631 |
| Eczema in the last 12 months | 185 | 1.46 | 1.01–2.11 | 0.043 | 186 | 1.34 | 0.96–1.87 | 0.085 | 0.882 |
| Doctor diagnosed allergic rhinitis | 186 | 1.27 | 0.61–2.64 | 0.528 | 186 | 3.44 | 1.82–6.47 | 0.000 | 0.969 |
| Skin prick tests | |||||||||
| Any of 11 inhalant and food allergens | 181 | 1.34 | 1.00–1.80 | 0.054 | 186 | 0.90 | 0.67–1.21 | 0.493 | 0.042 |
| Inhalant allergen | 181 | 1.40 | 1.04–1.89 | 0.029 | 186 | 0.91 | 0.67–1.23 | 0.544 | 0.027 |
| Ingested allergen | 181 | 0.51 | 0.10–2.63 | 0.424 | 186 | 1.28 | 0.55–2.99 | 0.571 | 0.695 |
| House dust mite (HDM) | 181 | 1.74 | 1.22–2.48 | 0.002 | 186 | 1.03 | 0.76–1.41 | 0.840 | 0.015 |
| Alternaria tenuis | 181 | 0.27 | 0.11–0.64 | 0.003 | 186 | 0.96 | 0.51–1.82 | 0.906 | 0.567 |
| Grass mix | 181 | 1.34 | 0.71–2.55 | 0.368 | 186 | 1.04 | 0.56–1.92 | 0.910 | 0.963 |
| Rye Grass | 181 | 1.33 | 0.70–2.53 | 0.382 | 185 | 1.08 | 0.66–1.78 | 0.761 | 0.906 |
| HDM-specific cytokines | |||||||||
| IL-5 (> 10 pg/ml) | 139 | 1.83 | 1.21–2.76 | 0.004 | 139 | 0.65 | 0.38–1.11 | 0.117 | 0.003 |
| IL-10 (> 10 pg/ml) | 131 | 1 | 0.83–1.22 | 0.969 | 133 | 0.98 | 0.83–1.16 | 0.817 | 0.981 |
All models are adjusted for sex, father’s education, mother’s education, environmental tobacco smoke exposure, breastfed to 6 months, any dog owned by 5 or 8 years, any cat owned by 5 or 8 years, maternal smoking in pregnancy, gas cooking at home
Interaction term of fish oil supplementation with weighted road density was added as a separate term into a Poisson model
Mean difference, Relative Risks (RRs) and 95% confidence intervals (95% CI) represent increase in risk per unit increase in weighted road density, representing 100 m local road or 33.3 m of motorway within 50 m of the home. N = number of children