Intention-to-treat analyses: Prevalence and effect estimates of primary and secondary outcomes at age 6 years follow-up by allocation group.

aData are numerator/denominator (%).bMean ± standard deviation.cMedian (range).dNo baseline measurement available. Numbers of children does not equal the sum of the denominators in each subgroup because only those with baseline and follow-up data are included. Measurements on FeNO and Rint were available for respectively 3497 (45%) and 3828 (49%) of the participating children. FeNO = Fractional exhaled Nitric Oxide, Rint = airway resistance, ETS = Environmental Tobacco Smoke. *Adjusted for randomisation stratum, and baseline prevalence of outcomes. Care as usual is the reference group.