Table 1. Sociodemographic characteristics, infant birth and neonatal data and chronic conditions at 12 years of age.
| EPT | Control | P value | |
|---|---|---|---|
| N = 132 | N = 103 | ||
| Maternal agea | 29.9 (5.3) | 30.2 (4.8) | ns |
| Adults in home | ns | ||
| Single-parent family, n (%) | 19 (14.4) | 8 (7.8%) | ns |
| Two-parent family, n (%) | 113 (85.6) | 95 (92.2%) | ns |
| Biological parents, n (%) | 80 (60.6) | 74 (71.8) | ns |
| Non-Nordic country of birth | |||
| Maternal, n (%) | 20 (15.2) | 8 (7.8) | ns |
| Paternal, n (%) | 16 (12.3) | 11 (10.9) | ns |
| Both parents, n (%) | 12 (9.1) | 5 (4.9) | ns |
| Maternal education, y | .016 | ||
| < 9, n (%) | 18 (13.6) | 4 (3.8) | .04 |
| 10–12, n (%) | 68 (51.5) | 44 (42.7) | ns |
| >12, n (%) | 46 (34.8) | 55 (54.5) | ns |
| Paternal education, y | ns | ||
| < 9, n (%) | 15 (12.5) | 4 (4.1) | ns |
| 10–12, n (%) | 69 (57.5) | 55 (56.2) | ns |
| > 12, n (%) | 36 (30) | 39 (39.8) | ns |
| Not known, n | 12 | 4 | |
| Family income, mean (SD), USD | 4399 (1910) | 4645 (1608) | ns |
| Low income, n (%) | 40 (27) | 27 (26) | ns |
| Social risk, anyb, n (%) | 50 (37.9) | 32 (31) | ns |
| Age at assessment, mean (SD), y | 11.96 (1.7) | 12.09 (1.9) | ns |
| Range, y | 10.1–15.6 | 10.3–15.9 | ns |
| Perinatal data | |||
| Gestational age, mean (SD) | 24.4 (0.7) | 39.4 (1.29) | < .001 |
| 23 weeks, n | 16 | na | |
| 24 weeks, n | 42 | na | |
| 25 weeks, n | 74 | na | |
| Female, n (%) | 72 (54.5) | 51 (49.5) | ns |
| Birth weight, mean (SD), g | 718 (129) | 3621 (498) | ns |
| Multiple birth, n (%) | 23 (17.4) | na | |
| SGAc, n (%) | 21 (15.9) | na | |
| Born at a tertiary care center, n (%) | 132 (100) | 132 (100) | |
| Antenatal steroids, any, n (%) | 92 (69.7) | na | |
| Antenatal steroids, full course | 57 (43.2) | na | |
| Surfactant, n (%) | 100 | na | |
| Neonatal survival, n (%) | 66 | na | |
| Chronic medical or psychiatric condition at 12 y, ≥ 1, n (%) d, e | 70 (53) | 19 (18.4) | < .001 |
| Chronic medical condition at 12 y, n (%)d,f | 55 (41.7) | 17 (16.5) | < .001 |
| Chronic psychiatric condition at 12 y, n (%)d | 20 (15.2) | 2 (1.9) | < .001 |
| Major neurosensory impairment at 12 y, n (%)d,g | 17 (12.9) | 0 | < .001 |
| Full-scale IQ, mean (SD), WISC-III-R | 80.3 (18.7) | 104.6 (15.7) | < .001 |
EPT, extremely preterm (23–25 weeks); NSI, neurosensory impairment; ns, not significant; na, not applicable.
a Mother’s age at birth of EI child or control child.
b In calculation of the composite social risk score, 1 point was assigned for each of following: single status, mother’s education of <9 years, and low income.
c SGA indicates ‘small for gestational age’ (birth weight of less than -2 SD) [38].
d Data adapted from ref. no. 36.
e Includes NSI or other medical or psychiatric illness lasting for ≥12 months.
f Includes NSI or other medical illness (excluding psychiatric illness) lasting for ≥ 12 months.
g Includes 1 or more of the following: moderate or disabling cerebral palsy (CP); severe visual impairment, including visual acuity of <20/200 without glasses in the best eye and registration at a low-vision center; severe auditory impairment in both ears not corrected with a hearing aid; and hearing loss corrected partially or fully with a hearing aid or an implant.