Table 1

Characteristics of the study population, the Espoo Cohort Study (n=2568)*

Characteristicn%
Sex of child
 Female125748.9
 Male131151.1
Duration of breast feeding, months
 <448119.3
 4–767026.9
 ≥8133753.7
Duration of pregnancy, weeks
 <371957.8
 ≥37230192.2
Maternal smoking during pregnancy
 No219985.8
 Yes36414.2
Family socioeconomic status
 Low66726.1
 Medium/high188973.9
Atopy
 No227688.6
 Yes29211.4
Parental atopy
 No169766.1
 Yes87133.9
Secondhand tobacco smoke exposure
 No217184.5
 Yes39715.5
Indoor mould exposure
 No242894.6
 Yes1385.4
  • *Missing value in the duration of breast feeding (n=79), duration of pregnancy (n=72), maternal smoking (n=5), family socioeconomic status (n=12) and indoor mould exposure (n=2).