Table 1.
Study group characteristics, final samples (mean/standard deviation)
| Measure | HR n = 29 | LR n = 15 | Pairwise comparison ( P value a ) |
|---|---|---|---|
| Age (days) | 312/15 | 313/14 | .807 |
| MSELb total score | 99/13 | 98/11 | .887 |
| MSEL VRc | 53/9 | 54/9 | .738 |
| MSEL FMd | 56/10 | 55/10 | .720 |
| MSEL RLe | 45/11 | 44/11 | .911 |
| MSEL ELf | 43/10 | 43/10 | .996 |
| SESg | −0.1/1.0 | 0.1/1.0 | .598 |
| Eye colorh | 1.5/1.0 | 1.3/0.9 | .656 |
aIndependent samples t-test; bMullen Scales of Early Learning (MSEL); cvisual reception (VR) subscale; dfine motor (FM) subscale; ereceptive language (RL) subscale; fexpressive language (EL) subscale; gsocioeconomic status (SES), calculated on the basis of parental education and income (equal weight), expressed as z-score; hExperimenter rated (0 to 3, 3 = darkest); high risk (HR); low risk (LR).