Table 1 Socio-demographic and clinical characteristics of the Dutch and the UK sample
|  | Dutch sample N = 253 | UK sample N = 91 |
|---|---|---|
Age in years, mean ± SD (range) | 11.06 ± 2.87 (7–18) | 12.09 ± 1.84 (9–15) |
Gender, n (%) | ||
 Male | 150 (59.3) | 52 (57.1) |
 Female | 103 (40.7) | 39 (42.9) |
Level of VI | ||
 VI0: logMAR ≤0.47 | 126 (49.8) | – |
 VI1: logMAR 0.48–0.70 | 56 (22.1) | 42 (46.2) |
 VI2: logMAR 0.71–1.00 | 35 (13.8) | 31 (34.1) |
 SVI: logMAR 1.01–1.30 | 4 (1.6) | 10 (11.0) |
 Blind: logMAR ≥1.31 | 24 (9.5) | 8 (8.8) |
 Unknown | 8 (3.2) | – |
Nationality | ||
 Ethnic majority | 228 (90.1) | 77 (84.6) |
 Ethnic minortiy | 25 (9.9) | 14 (15.4) |
Other impairment, n (%) | ||
 Yes | 117 (46.2) | 28 (30.8) |
 No | 124 (49.0) | 62 (68.1) |
 Unknown | 12 (4.7) | 1 (1.1) |
Siblings, n (%) | ||
 No | 29 (11.5) | 6 (6.6) |
 One | 119 (47.0) | 49 (53.8) |
 Two or more | 93 (36.8) | 33 (36.3) |
 Unknown | 12 (4.7) | 3 (3.3) |
Siblings with VI, n (%) | ||
 Yes | 41 (16.2) | 21 (23.1) |
 No | 171 (67.6) | 61 (67.0) |
 N/A (no/unknown siblings) | 41 (16.2) | 9 (9.9) |