(Overall Sample) Univariate and multivariate linear regression for spirometry and total IgE (kU/L) and Poisson regression with robust standard error analyses for AHR, eNO, questionnaire outcomes (all) in relation to weighted road density within 50 m radius of home.

Relative Risks (RRs) and percent difference (B) expressed per unit increase in weighted road density variable, where one unit relates to 100 m local road or 33.3 m of motorway within given radius of the home.
Lung function variables are logged, therefore percent differences by B = 100(eβ−1) are presented for each unit increase in weighted road density, where β is the regression coefficient from linear regression analyses for continuous variables.
RR is the Relative Risk per unit increase in weighted road density from Poisson regression with robust standard errors conducted on binary variables.
‡Multivariate analyses are adjusted for sex, father's education, mother's education, environmental tobacco smoke exposure, breastfed to 6 months, any dog owned by 8 years, any cat owned by 8 years, maternal smoking in pregnancy, gas cooking at home. Univariate and multivariate lung function analyses included adjustment for age, height and weight.
‡‡p-value from additional analysis where an interaction term of weighted road density and atopy was included in the model.