Table 1—

Characteristics of cases and noncases from the population at risk

Onset asthmaIncident asthma
Total n1163708583766
Males n411739181762
Females n7519690.014020040.02
BMI mean kg·m225.424.70.06+25.324.70.26+
Age in 1999 mean yrs39.439.70.61+39.739.70.97+
Smoking % never/former/current46/29/2551/25/240.50§41/32/2751/25/240.32§
Hay fever %48.718.6<0.00§40.419.2<0.00§
Water/mould# %24.323.20.74§20.723.30.76§
  • The table includes those who received a modelled value of nitrogen dioxide and could be classified as cases or noncases according to the definition of onset and incident asthma. BMI: body mass index. #: water damage or mould in the home at any time during the last 8 yrs; : Pearson’s Chi-squared test comparing the proportional difference of males and females among cases; +: unpaired t-test comparing cases with asthma with those without asthma; §: Pearson’s Chi-squared test comparing cases with asthma with those without asthma.