Table 3. Concentration: Digits Backward Testa.
| Characteristic | No. (%) | Mean Difference (95% CI) | Effect Size | ||||
|---|---|---|---|---|---|---|---|
| Boys (n = 241) |
Girls (n = 233) |
Age, y | |||||
| 5-7 (n = 63) |
8-10 (n = 221) |
11-13 (n = 190) |
|||||
| Digits, No. | |||||||
| None | 4 (1.7) | 2 (0.9) | 4 (6.3) | 0 | 2 (1.1) | NA | NA |
| 2b | 13 (5.4) | 13 (5.6) | 7 (11.1) | 18 (8.1) | 1 (0.5) | NA | NA |
| 3 | 63 (26.1) | 53 (22.7) | 32 (50.8) | 55 (24.9) | 29 (15.3) | NA | NA |
| 4 | 94 (39.0) | 68 (29.2) | 18 (28.6) | 78 (35.3) | 66 (34.7) | NA | NA |
| 5 | 42 (17.4) | 55 (23.6) | 2 (3.2) | 44 (19.9) | 51 (26.8) | NA | NA |
| 6 | 25 (10.4) | 42 (18.0) | 0 | 26 (11.8) | 41 (21.6) | NA | NA |
| Score (range, 0-5) | |||||||
| Mean (SD) | 3.2 (1.2) | 3.0 (1.1) | 2.1 (0.9) | 3.0 (1.1) | 3.5 (1.1) | NA | NA |
| Sex | NA | NA | NA | NA | NA | 0.27 (0.06 to 0.48) | 0.23 |
| Age, y | |||||||
| 5-7 vs 8-10 | NA | NA | NA | NA | NA | −0.91 (−1.21 to −0.61) | −0.85 |
| 5-7 vs 11-13 | NA | NA | NA | NA | NA | −1.39 (−1.69 to −1.10) | −1.35 |
| 8-10 vs 11-13 | NA | NA | NA | NA | NA | −0.48 (−0.70 to −0.27) | −0.44 |
Abbreviation: NA, not applicable.
a
A higher score indicates more correct digits backward.
b
The Digits Backward section starts with 2 digits, not 1.