Table 3

Mutually adjusted analyses for reversible and irreversible airflow limitation which included age, gender, body mass index and other related factors*

VariablesNormal lung functionIrreversible airflow limitation
No of individuals/casesOR (95% CI)No of individuals/casesOR (95% CI)
NOx concentration during age 0–1 years†, high versus low1261/6511 (Reference)29/223.08 (1.11 to 8.51)
NOx concentration during age 12–16 years†, high versus low1261/6371 (Reference)29/212.12 (0.82 to 5.46)
RSV infection/pneumonia during infancy1261/841 (Reference)29/83.59 (1.41 to 9.14)
Childhood asthma during age 0–4 years1261/1271 (Reference)29/83.36 (1.22 to 9.24)
Childhood asthma during age 4–8 years1261/781 (Reference)29/20.32 (0.06 to 1.81)
Childhood asthma during age 8–12 years1261/821 (Reference)29/10.16 (0.02 to 1.43)
Childhood asthma during age 12–16 years1261/781 (Reference)29/31.31 (0.32 to 5.44)
Current asthma1261/1441 (Reference)29/73.51 (1.22 to 10.15)
VariablesNormal lung functionReversible airflow limitation
Parental asthma1317/2531 (Reference)77/282.17 (1.31 to 3.58)
NOx concentration during age 8–12 years†, high versus low1317/6541 (Reference)77/340.82 (0.51 to 1.32)
Childhood asthma during age 0–4 years1317/1371 (Reference)77/141.37 (0.68 to 2.75)
Childhood asthma during age 4–8 years1317/841 (Reference)77/90.92 (0.36 to 2.34)
Childhood asthma during age 8–12 years1317/881 (Reference)77/101.22 (0.50 to 2.97)
Childhood asthma during age 12–16 years1317/871 (Reference)77/101.21 (0.51 to 2.86)
Current asthma1317/1541 (Reference)77/161.49 (0.72 to 3.11)
  • *Details about the definitions of covariates are provided in the online supplemental file.

  • †The median NOx concentration for ages 0–1, 8–12 and 12–16 years were 29.16, 13.66 and 11.16 µg/m3.

  • NOx, nitrogen oxides; RSV, respiratory syncytial virus.