Characteristics of children in the cognitive cohort in control and intervention schools at baseline: November 2010 (classes 4 and 5 only)
| Control schools | Intervention schools | |
| Number of schools surveyed | 40 | 40 |
| Number of children surveyed | 600 | 597 |
| School-level characteristics: | ||
| School size: mean no. of pupils (SD) | 167.3 (21.2) | 158.5 (18.7) |
| Individual-level characteristics: | ||
| Mean age in years (SD) | 10.0 (1.2) | 10.4 (1.4) |
| Proportion Female | 47.0% (282/600) | 44.2% (264/597) |
| Enrolled in class 5 | 27.5% (165/600) | 37.3% (222/597) |
| Study endpoints at baseline: cognitive | ||
| Code transmission: single-digit task, z-score | 0.069 (1.00) | −0.069 (0.99) |
| Code transmission: double-digit task, z-score | 0.035 (0.96) | −0.035 (1.04) |
| Visual search task, z-score | −0.049 (0.99) | 0.049 (1.00) |
| Numeracy task, z-score | −0.013 (1.00) | 0.013 (1.00) |
| Vocabulary task, z-score | 0.029 (1.02) | −0.029 (0.97) |
| Writing task, z-score | 0.037 (0.94) | −0.037 (1.05) |
Data are mean (SD), or % (n/N), unless specified otherwise.