Table 1 Characteristics of the sample by predictor domains and their correlations with IQ at 4 years of age
Correlation with IQ at 4 years of age | |||
|---|---|---|---|
Indicators of the sample N = 114 | Descriptive statistics of variables | correlation coefficient (r) | significance (p) |
Demographic variables of parents | |||
Maternal education (primary, %) | 14.91 | 0.492 | < 0.001 |
Family wealth (below average, %) | 6.14 | 0.392 | < 0.001 |
Ethnicity (Roma, %) | 11.40 | -0.315 | 0.001 |
Perinatal variables at birth | |||
Birth weight (mean ± SD) | 1310.08 (545.72) | 0.402 | < 0.001 |
Gestational age (mean ± SD) | 30.00 (3.85) | 0.295 | 0.001 |
Sex (Male, %) | 43.85 | -0.044 | 0.639 |
Twin pregnancy (yes, %) | 41.20 | 0.164 | 0.081 |
Apgar at 1 min. (mean ± SD) | 6.97 (1.74) | 0.245 | 0.014 |
Apgar at 5 min. (mean ± SD) | 8.24 (1.02) | 0.257 | 0.010 |
Smoking during pregnancy (yes, %) | 20.17 | -0.407 | < 0.001 |
Neonatal variables after birth | |||
Retinopathy of prematurity (yes, %) | 15.70 | -0.335 | < 0.001 |
Intraventricular haemorrhage (yes, %) | 12.28 | -0.242 | 0.010 |
Bronchopulmonary dysplasia (yes, %) | 14.91 | -0.408 | < 0.001 |
Developmental characteristics at 2 years of age | |||
BSID-III Raw scores | |||
Cognitive skills (mean ± SD) | 7.99 (2.76) | 0.623 | < 0.001 |
Receptive comm. (mean ± SD) | 8.51 (2.43) | 0.592 | < 0.001 |
Expressive comm. (mean ± SD) | 7.28 (2.67) | 0.342 | < 0.001 |
Fine motor skills (mean ± SD) | 8.50 (2.57) | 0.621 | < 0.001 |
Gross motor skills (mean ± SD) | 7.82 (2.47) | 0.495 | < 0.001 |
BSID-III Composite scores | |||
Cognitive skills (mean ± SD) | 90.17 (13.99) | 0.613 | < 0.001 |
Language skills (mean ± SD) | 88.18 (13.07) | 0.535 | < 0.001 |
Motor skills (mean ± SD) | 89.07 (13.77) | 0.632 | < 0.001 |
Mean performance | |||
∑Cog.-Lang.-Mot.a (mean ± SD) | 89.14 (11.85) | 0.683 | < 0.001 |