Table 1

 Distribution of variables among children included and excluded from the analyses. Values are means (SD) unless stated otherwise

Included, mean (SD)nExcluded, mean (SD)np value
*Defined as the most deprived quarter of population according to Townsend scores.
Age at final exam (years)6.94 (0.25)13356.94 (0.25)5800.89
Male sex (%)49.2%133550.8%19170.39
First born (%)42.6%133541.7%19170.62
Ever breast fed (%)54.3%123046.8%1321<0.001
Socially deprived* (%)22.5%130626.0%18080.026
Body size indices
    Birth weight (kg)3.40 (0.46)13353.41 (0.45)19160.48
    Birth weight (z score)−0.04 (0.95)1335−0.02 (0.92)19160.54
    6 week weight (z score)0.18 (1.17)13350.16 (1.16)12510.58
    18 month weight (z score)0.35 (1.35)13350.39 (1.42)11570.86
    Weight at age 7 (z score)0.27 (1.55)13350.26 (1.48)5740.90
    Height at age 7 (z score)0.05 (1.01)13350.06 (1.00)5750.82
    BMI at age 7 (z score)0.02 (0.99)13350.02 (0.97)5740.90