TABLE 2

Association expressed as risk relative ratio (RRR) between childhood, parental factors, air pollution exposure and forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and FEV1/FVC lung function trajectories in Raine participants with two or more spirometry measurements

VariableFEV1 (n=1512) RRR (95% CI)FVC (n=1512) RRR (95% CI)FEV1/FVC (n=1512) RRR (95% CI)
Average (reference category)Average (reference category)Average (reference category)
Very low (n=51)Low (n=746)Above average (n=104)Very low (n=61)Low (n=855)Above average (n=139)Very low (n=131)Low-average (n=198)Average-low (n=529)
Females0.61 (0.34–1.10)1.03 (0.84–1.29)0.88 (0.58–1.33)0.67 (0.39–1.15)1.04 (0.83–1.31)0.88 (0.60–1.29)0.83 (0.57–1.22)1.17 (0.85–1.61)0.80 (0.63–1.01)
SES
 16 000–40 0002.24 (0.66–7.61)0.97 (0.65–1.43)1.33 (0.60–2.98)2.13 (0.62–7.35)0.84 (0.54–1.29)0.67 (0.35–1.28)1.05 (0.52–2.13)0.60 (0.33–1.07)0.77 (0.51–1.18)
 ≥40 0001.09 (0.66–7.61)1.06 (0.72–1.55)1.11 (0.50–2.51)1.43 (0.41–5.01)0.82 (0.53–1.25)0.62 (0.33–1.19)0.91 (0.45–1.85)0.95 (0.54–1.67)0.74 (0.48–1.21)
Preterm1.04 (0.31–3.51)1.30 (0.84–2.01)0.97 (0.30–2.37)1.51 (0.60–3.79)1.03 (0.38–1.62)0.85 (0.38–1.90)0.94 (0.38–2.30)2.03 (1.11–3.71)1.92 (1.19–3.08)
Birthweight1.59 (0.80–3.17)0.80 (0.59–1.08)0.63 (0.29–1.37)1.66 (0.74–3.76)0.95 (0.63–1.44)0.67 (0.31–1.48)0.97 (0.44–2.13)1.77 (1.02–3.08)1.63 (0.90–2.50)
Respiratory infections
 URTI only0.41 (0.18–3.56)0.82 (0.64–1.06)1.25 (0.76–2.04)0.55 (0.28–1.99)1.02 (0.78–1.34)1.30 (0.84–2.02)0.82 (0.52–1.29)1.07 (0.74–1.56)0.93 (0.71–1.22)
 LRTI or both1.49 (0.75–2.93)1.06 (0.79–1.43)1.30 (0.72–2.34)1.02 (0.52–1.99)1.08 (0.79–1.48)1.04 (0.61–1.77)0.99 (0.60–1.63)1.04 (0.67–1.62)1.00 (0.73–1.38)
Asthma at age 6 years2.07 (0.90–4.74)1.68 (1.20–2.36)0.89 (0.42–1.90)0.97 (0.44–2.16)1.02 (0.72–1.44)0.93 (0.51–1.67)3.31 (2.01–5.47)1.98 (1.21–3.24)1.57 (1.08–2.28)
Atopy (IgE) at age 6
 Food allergy (only)1.20 (1.15–9.75)1.16 (0.52–2.56)1.20 (0.26–2.57)–#1.41 (0.59–3.41)1.42 (0.36–6.64)–#2.35 (0.82–6.77)1.90 (0.81–4.46)
 Aeroallergens only or both0.46 (0.17–1.24)0.96 (0.72–.1.27)1.37 (0.81–2.31)0.94 (0.46–2.92)0.95 (0.59–3.41)1.23 (0.76–1.97)0.74 (0.45–1.22)0.77 (0.50–1.19)0.70 (0.51–0.95)
Maternal smoking
 Smoking in pregnancy  only1.07 (0.24–4.83)0.72 (0.40–1.32)1.75 (0.75–4.06)1.38 (0.38–5.01)0.69 (0.37–1.30)1.57 (0.70–3.56)2.22 (0.90–5.50)1.25 (0.51–3.02)1.38 (0.74–2.58)
 Smoking at age 6 only0.34 (0.04–2.70)1.07 (0.70–1.62)0.35 (0.11–1.18)1.61 (0.57–4.56)1.42 (0.88–2.31)0.45 (0.15–1.33)1.05 (0.47–2.34)0.92 (0.47–1.79)0.90 (0.56–1.43)
 Both1.40 (0.66–2.96)1.12 (0.83–1.51)0.57 (0.29–1.13)1.23 (0.61–2.47)0.73 (0.53–1.14)0.69 (0.37–1.30)2.47 (1.52–2.50)1.35 (0.85–2.14)0.77 (0.55–1.09)
Parental asthma
 Mother asthma only1.29 (0.52–3.20)1.02 (0.70–1.49)0.67 (0.31–1.47)1.94 (0.79–4.80)0.91 (0.60–1.35)0.62 (0.32–1.21)0.92 (0.48–1.75)0.88 (0.49–1.57)0.74 (0.50–1.10)
 Father asthma only1.04 (0.31–3.47)1.14 (0.73–1.80)0.34 (0.10–1.19)1.99 (0.67–5.91)1.13 (0.69–1.84)0.61 (0.25–1.45)0.99 (0.46–2.11)0.84 (0.41–1.71)1.49 (0.91–2.45)
 Both–#1.82 (0.80–4.12)0.56 (0.07–4.73)2.41 (0.43–3.49)1.19 (0.50–2.80)0.27 (0.03–2.28)0.99 (0.25–3.93)1.27 (0.37–4.35)1.76 (0.73–4.26)
Parental hay fever
 Mother hay fever1.06 (0.59–1.92)0.84 (0.62–1.13)1.06 (0.59–1.92)0.97 (0.45–2.07)0.79 (0.46–1.37)1.06 (0.62–1.81)0.59 (0.34–1.03)0.89 (0.57–1.37)0.96 (0.70–1.32)
 Father hay fever0.56 (0.21–1.49)0.73 (0.52–1.02)1.04 (0.54–2.03)0.82 (0.47–1.43)0.97 (0.43–2.23)1.04 (0.57–1.88)1.27 (0.72–2.23)1.17 (0.71–1.92)1.26 (0.87–1.32)
 Both0.49 (0.17–1.43)0.72 (0.50–1.04)1.38 (0.70–2.71)0.82 (0.31–2.17)0.76 (0.51–1.12)1.60 (0.87–2.95)0.76 (0.40–1.45)0.99 (0.58–1.68)0.99 (0.67–1.46)
Parental eczema
 Mother eczema only0.41 (0.12–1.40)1.06 (0.78–1.46)0.73 (0.37–1.45)0.81 (0.46–1.41)0.88 (0.40–1.94)0.75 (0.54–1.04)1.35 (0.79–2.31)0.72 (0.44–1.18)0.97 (0.69–1.37)
 Father eczema only1.59 (0.52–4.88)1.47 (0.92–2.36)0.98 (0.36–2.62)0.71 (0.28–1.80)1.66 (0.63–4.39)1.10 (0.67–1.80)2.38 (1.20–4.72)0.88 (0.42–1.83)1.26 (0.76–2.08)
 Both0.41 (0.12–1.40)1.06 (0.78–1.46)0.73 (0.37–1.45)0.81 (0.46–1.41)0.88 (0.40–1.94)0.75 (0.54–1.04)1.35 (0.79–2.31)0.72 (0.44–1.18)0.97 (0.69–1.37)
PM2.5Abs0.29 (0.09–1.06)1.63 (1.06–2.51)1.09 (0.57–2.08)0.74 (0.29–1.88)0.99 (0.54–1.81)0.97 (0.65–1.44)0.62 (0.33–1.17)0.58 (0.33–1.01)0.52 (0.35–0.79)
NO20.78 (0.66–1.10)0.95 (0.90–1.01)1.04 (0.93–1.17)0.91 (0.79–1.06)1.04 (0.94–1.15)1.02 (0.95–1.08)0.96 (0.86–1.06)0.94 (0.86–1.02)0.90 (0.84–0.96)

RRR (95% CI) and significant differences from the average trajectory were derived from a multinomial logistic regression. Bold values indicate a significant association at α=0.05. For asthma, model was adjusted for maternal smoking, parental asthma, sex and socioeconomic status. For atopy, model was adjusted for childhood asthma, parental asthma, parental hay fever, parental wheezing, sex and socioeconomic status. For respiratory tract infections, model was adjusted for maternal smoking, sex and socioeconomic status. For maternal smoke, model was adjusted for childhood asthma, maternal asthma and socioeconomic status. For parental asthma, model was adjusted for parental hay fever, parental eczema, parental wheezing, sex and socioeconomic status. For parental hay fever, model was adjusted for parental asthma, parental wheezing, sex and socioeconomic status. For parental eczema, model was adjusted for parental asthma, parental hay fever, sex and socioeconomic status. For PM2.5Abs and nitrogen dioxide (NO2), model was adjusted for childhood asthma, childhood hay fever, parental eczema, parental wheezing, sex and socioeconomic status. The average trajectory of FEV1, FEV1/FVC and FVC were used as reference category. SES: socioeconomic status; LRTI: low respiratory tract infections in the first year of life; URTI: upper respiratory tract infections in the first year of life; Ig: immunoglobulin. #: low number of participants in the category.