Demographic characteristics of children by recruitment source
| Characteristic | Recruited via audiology services (intended cases) (N=75) | Recruited via schools (intended controls) (N=240) |
| Male, n (%) | 38 (51) | 117 (49) |
| Age, mean (SD; range) | 5.4 (0.9; 3.9 to 7.0) | 5.4 (0.6; 4.0 to 6.9) |
| Ethnicity | ||
| White, n (%) | 61 (81) | 189 (79) |
| Black, n (%) | 2 (3) | 14 (6) |
| Asian, n (%) | 11 (15) | 10 (4) |
| Mixed, n (%) | 1 (1) | 22 (9) |
| Other, n (%) | 0 (0) | 5 (2) |