Table 1.
Background characteristics: Comparison of current preterm‐born and control samples, and groupwise dropouts
| VP/VLBW | Controls | |||||||
|---|---|---|---|---|---|---|---|---|
| Current sample (n = 73) | Not included (n = 338) | Within group: P | Current sample (n = 73) | Not included (n = 235) | Within group: P | Between Current samples: P | ||
| Sex: | Male | n = 44 (60%) | n = 168 (50%) | ns | n = 45 (62%) | n = 109 (46%) | <0.05 | ns |
| Female | n = 29 (40%) | n = 170 (50%) | n = 28 (38%) | n = 126 (54%) | ||||
| Age at examination (years) | 26.5 ± 0.49 | — | — | 26.51 ± 0.53 | — | — | ns | |
| Gestational age (months) | 30.3 ± 2.1 | 30.58 ± 2.34 | ns | 39.85 ± 1 | 39.58 ± 1.23 | ns | <0.001 | |
| Birth weight (grams) | 1331 ± 318 | 1296 ± 305 | ns | 3439 ± 432 | 3366 ± 449 | ns | <0.001 | |
| Maternal age (years) | 29.53 ± 4.42 | 28.3 ± 5.1 (n = 337) | <0.05 | 29.56 ± 5.18 | 28.4 ± 4.7 (n = 234) | ns | ns | |
| Socioeconomic status at birth | Upper | n = 22 (30%) | n = 59 (18%) | <0.05 | n = 25 (34%) | n = 67 (29%) | ns | ns |
| Middle | n = 32 (44%) | n = 141 (42%) | n = 29 (40%) | n = 93 (40%) | ||||
| Lower | n = 19 (26%) | n = 137 (41%) | n = 19 (26%) | n = 75 (32%) | ||||
| Optimality : neonatal | 8.75 ± 2.57 | 9.52 ± 2.71 (n = 336) | <0.05 | 0.33 ± 0.58 | 0.4 ± 0.67 | ns | <0.001 | |
| Duration of hospitalization | 71.52 ± 26.75 | 78.86 ± 38.28 | ns | 6.93 ± 3.23 | 7.34 ± 3.79 (n = 234) | ns | <0.001 | |
| Griffith Scales of Baby Abilities | 5 months | 101.3 ± 17.2 (n = 72) | 94.11 ± 20.95 (n = 312) | <0.01 | 106.2 ± 11 | 106.49 ± 10.79 | ns | <0.05 |
| 20 months | 99.31 ± 10.7 (n = 71) | 90.12 ± 22.53 (n = 299) | <0.001 | 106.4 ± 6.5 | 106.38 ± 6.72 | ns | <0.001 | |
| Kaufman Assessment Battery for Children | 6;3 years | 92.6 ± 11.5 (n = 64) | 83.98 ± 16.88 (n = 267) | <0.001 | 102.4 ± 10.6 | 99.97 ± 11.19 | ns | <0.001 |
| 8;5 years | 96.7 ± 11.2 (n = 69) | 86.01 ± 18.7 (n = 272) | <0.001 | 102.7 ± 9.6 (n = 72) | 100.36 ± 10.2 (n = 233) | ns | 0.001 | |
Within‐group analyses compared present preterm‐born (VP/VLBW) and term‐born (Controls) samples with those preterm‐born and term‐born participants, respectively, not included in this study. Between‐group analyses compared current preterm‐born and term‐born samples. For variables where data were not available for all participants, the actual group size is indicated separately.