Table 3

 Multivariable associations of birth weight with FEF25–75

Difference (95% confidence interval) in FEF25–75 (l)
Model 1*Model 2†Model 3‡Model 4§
FEF25–75, forced expiratory flow rate during mid expiration.
*Model 1: adjusted for age and examining nurse.
†Model 2: adjusted for age, examining nurse and height squared.
‡Model 3: adjusted for age, examining nurse, height squared, father’s occupational social class, whether childhood house had a bathroom, whether childhood house had hot water, family access to a car in childhood, whether the participant shared a bedroom as a child, age at leaving full time education, adult occupational social class, adult car access, adult home ownership, pension arrangements.
§Model 4: adjusted for all factors in model 3 and adult smoking.
Lowest quarter birth weight,range 739–2826 g (N = 746)ReferenceReferenceReferenceReference
2nd quarter birth weight,range 2827–3352 g (N = 476)0.05 (−0.04 to 0.14)0.01 (−0.08 to 0.10)−0.01 (−0.10 to 0.08)−0.01 (−0.10 to 0.08)
3rd quarter birth weight,range 3353–3735 g (N = 774)0.07 (−0.01 to 0.15)0.01 (−0.07 to 0.09)0.01 (−0.07 to 0.09)0.00 (−0.08 to 0.08)
Highest quarter birth weight,range 3736–5909 g (N = 435)0.08 (−0.01 to 0.18)0.00 (−0.09 to 0.10)−0.01 (−0.11 to 0.08)−0.02 (−0.12 to 0.07)
Per 1 kg birth weight0.05 (0.01 to 0.09)0.01 (−0.03 to 0.05)0.01 (−0.04 to 0.05)0.00 (−0.04 to 0.04)
P linear trend0.030.670.780.88
p non-linear association0.910.940.990.98
Per 1 kg excluding those in lowest birth weight quarter0.04 (−0.04 to 0.11)0.01 (−0.06 to 0.08)0.01 (−0.07 to 0.08)0.01 (−0.07 to 0.08)