TABLE 3.
Neurocognitive test performance of children with SCA and comparison children
| Cognitive measures | SCA(n = 42–53), mean (SD) | Percent missing | Comparisons (n = 27–41), mean (SD) | Percent missing | d | P-valueb | Adjusted P-valuec |
|---|---|---|---|---|---|---|---|
| Estimated IQa | 84.58 (15.32) | 25.0 | 96.10 (18.28) | 38.6 | −0.68 | 0.006 | 0.008 |
| Working memory | 88.63 (13.90) | 17.9 | 94.69 (13.90) | 34.1 | −0.44 | 0.070 | 0.174 |
| Processing speed | 86.69 (15.72) | 14.3 | 96.91 (18.21) | 25.0 | −0.60 | 0.009 | 0.001 |
| Coding | 7.70 (3.14) | 5.4 | 9.95 (3.98) | 6.8 | −0.63 | 0.003 | <0.001 |
| Symbol search | 7.34 (3.47) | 10.7 | 9.15 (3.22) | 25.0 | −0.54 | 0.019 | 0.006 |
| Letter numbering | 6.00 (3.30) | 16.1 | 6.67 (3.54) | 31.8 | −0.20 | 0.403 | 0.393 |
| Digit span | 10.06 (3.49) | 5.4 | 12.73 (3.60) | 9.1 | −0.75 | 0.001 | <0.001 |
a
Est. IQ was derived from four subtest short forms. The scaled scores of the four subtests and the composite scores of the primary outcomes are reported.25 Effect sizes (Cohen’s d) were calculated by dividing the difference of two sample means by the pooled standard deviation of the two groups.
b
Independent sample t-test.
c
P-value for the association between cognitive measure and presence of SCA, from a linear regression model with each cognitive measure as an outcome and both presence of SCA and father’s education ≥OND/NCE as binary predictors.