Table 2

Associations of any upper and lower respiratory tract infections with lung function and asthma at age 10 years

  FEV1
  Z-score (95% CI)
  n=4672
  FVC
  Z-score (95% CI)
  n=4672
  FEV1:FVC
  Z-score (95% CI)
  n=4672
  FEF75
  Z-score (95% CI)
  n=4672
  Current asthma
  OR (95% CI)
  n=4556
Any URTI
 Age 6 monthsn=2930−0.02 (−0.13 to 0.10)−0.04 (−0.15 to 0.07)0.02 (−0.09 to 0.14)0.00 (−0.11 to 0.11)1.46 (0.93 to 2.28)
 Age 1 yearn=3601−0.03 (−0.12 to 0.07)−0.02 (−0.11 to 0.07)−0.02 (−0.11 to 0.08)−0.03 (−0.12 to 0.05)1.42 (0.96 to 2.12)
 Age 2 yearsn=37680.06 (−0.03 to 0.16)0.04 (−0.05 to 0.12)0.04 (−0.05 to 0.13)0.05 (−0.04 to 0.14)1.56 (1.04 to 2.34)*
 Age 3 yearsn=36450.03 (−0.08 to 0.13)0.06 (−0.04 to 0.16)−0.07 (−0.18 to 0.03)−0.05 (−0.15 to 0.05)1.04 (0.65 to 1.66)
 Age 4 yearsn=36580.01 (−0.11 to 0.14)−0.02 (−0.13 to 0.10)0.06 (−0.06 to 0.18)0.07 (−0.05 to 0.18)0.84 (0.48 to 1.46)
 Age 6 yearsn=46810.03 (−0.09 to 0.16)0.02 (−0.10 to 0.13)0.03 (−0.09 to 0.15)0.03 (−0.09 to 0.15)1.01 (0.57 to 1.79)
Any LRTI
 Age 6 monthsn=2996−0.21 (−0.35 to 0.07)**−0.12 (−0.26 to 0.01)−0.12 (−0.26 to 0.02)−0.11 (−0.24 to 0.02)1.66 (0.97 to 2.82)
 Age 1 yearn=3623−0.34 (−0.50 to –0.18)**−0.25 (−0.40 to –0.10)**−0.14 (−0.29 to 0.02)−0.25 (−0.40 to –0.10)**1.27 (0.86 to 2.87)
 Age 2 yearsn=3828−0.19 (−0.32 to –0.05)**−0.03 (−0.16 to 0.10)−0.25 (−0.38 to –0.12)**−0.28 (−0.40 to –0.15)**4.19 (2.65 to 6.64)**
 Age 3 yearsn=3678−0.21 (−0.41 to –0.01)*−0.07 (−0.26 to 0.11)−0.22 (−0.41 to –0.03)*−0.16 (−0.34 to 0.03)4.15 (2.33 to 7.42)**
 Age 4 yearsn=3649−0.08 (−0.32 to 0.16)0.03 (−0.20 to 0.25)−0.17 (−0.41 to 0.07)−0.13 (−0.35 to 0.10)7.80 (4.13 to 14.71)**
 Age 6 yearsn=46490.08 (−0.15 to 0.30)0.23 (0.02 to 0.45)*−0.27 (−0.49 to –0.05)*−0.15 (−0.36 to 0.07)13.45 (7.22 to 25.05)**
  • Values are Z-scores or ORs with 95% CI, derived from linear or binomial logistic regression models. Models are adjusted for maternal education, body mass index, parity, smoking during pregnancy, psychiatric symptoms during pregnancy, pet keeping, history of asthma or atopy, mode of delivery and child’s sex, gestational age at birth, birth weight corrected for gestational age at birth, breastfeeding and day care attendance. Additionally, upper respiratory tract infections were adjusted for any preceding upper respiratory tract infections, and lower respiratory tract infections for any preceding lower respiratory tract infections.

  • *p<0.05, **p<0.01.

  • LRTI, lower respiratory tract infection; URTI, upper respiratory tract infection.