Table. 4—

Multivariate# associations of selected factors with different operational definitions of asthma

Wheeze, breathlessness (binary)ECRHS definition (binary)Score (continuous)
ORLower 95% CIUpper 95% CIz-valueORLower 95% CIUpper 95% CIz-valueRelative change+Lower 95% CIUpper 95% CIz-value
Maternal asthma1.811.452.26 5.251.851.442.38 4.831.631.441.86 7.52
Atopy1.691.481.93 7.772.021.732.36 8.871.481.381.5910.55
BHR§4.824.185.5621.535.674.826.6521.153.042.793.3225.28
Current smoking1.931.672.23 8.821.110.931.32 1.181.521.401.6410.41
Ex-smoking1.140.951.37 1.461.170.961.42 1.551.151.051.26 2.91
Age 30–39 yrs0.910.791.05−1.320.970.821.15−0.380.940.871.01−1.68
Age >40 yrs0.970.811.16−0.301.221.001.50 1.941.040.941.14 0.74
Female1.100.971.25 1.421.040.891.20 0.451.201.121.29 5.23
  • ECRHS: European Community Respiratory Health Study; OR: odds ratio; CI: confidence intervals; BHR: bronchial hyperresponsivness. #: OR calculated using logistic regression and relative change in mean score using negative binomial model, adjusting for centre and all the other variables in the table; : any one of the three variables (woken by shortness of breath, attack of asthma, or asthma medication); +: for interpretation of the relative change, see statistical methods; §: 20% fall in forced expiratory volume in one second at 1 mg.