Characteristics of subjects
| Group | |||
|---|---|---|---|
| Cases | Hospital controls | GP controls | |
| Values are mean (SD). | |||
| *GP controls differed significantly from the other two groups. | |||
| GP, General practitioner. | |||
| Birth weight (g) | 2769 (815) | 2780 (782) | 3278 (499)* |
| Gestational age (weeks) | 36.9 (3.9) | 37.4 (4.2) | 39.8 (1.8)* |
| Age at examination (years) | 9.39 (0.24) | 9.42 (0.22) | 9.42 (0.26) |