Table 1

Characteristics of the sample entering the double blind, placebo controlled, crossover challenge

nHA/AT 36HA/non-AT 75Non-HA/AT 79Non-HA/non-AT 87
Females (%)14 (39)36 (48)35 (44)41 (47)
Mean age at baseline testing in years (range)3.6 (3.2–4.0)3.7 (3.2–4.00)3.7 (3.2–4.0)3.8 (3.2–4.1)
Children with behaviour problems (BCL) (%)24 (67)40 (53)11 (14)9 (10)
Mean maternal age at leaving full time education (range)17.9 (15–26)17.0 (15–25)18.0 (15–34)17.7 (15–30)