Distribution of variables in cases (children with developmental and behavioural problems) and controls
| Variable | Cases (n = 69) | Controls (n = 136) |
| Age (y) | 5.7 (2.7) | 7.1 (2.6) |
| % (n) females | 19 (13) | 54 (74) |
| Median lead level (interquartile range), μg/l | 38 (19 to 125) | 30 (10 to 76) |
| Meangeometric lead level, μg/l | 40.7 (1.9) | 29.2 (1.6) |
| Townsend material deprivation score | 1.1 (3.4) | 2.0 (3.5) |
Results expressed as mean (SD) unless stated otherwise.