Variables | Children assessed at 11 years (n=200) | Children not assessed at 11 years (n=831) | P value | |
Gestational age | ||||
22 weeks | % (n/N) | 0.0% (0/200) | 0.4% (3/831) | 0.536 |
23 weeks | % (n/N) | 7.5% (15/200) | 5.8% (48/831) | |
24 weeks | % (n/N) | 14.0% (28/200) | 17.9% (149/831) | |
25 weeks | % (n/N) | 34.5% (69/200) | 32.7% (272/831) | |
26 weeks | % (n/N) | 44.0% (88/200) | 43.2% (359/831) | |
Birth weight (g) | Mean (SD) | 810.2 (147.5) (n=200) | 794.5 (149.0) (n=831) | 0.181 |
Birth weight z scores | Mean (SD) | −0.2 (0.8) (n=200) | −0.3 (0.8) (n=828) | 0.163 |
Male sex | % (n/N) | 50.0% (100/200) | 48.0% (399/831) | 0.614 |
Multiple birth | % (n/N) | 24.5% (49/200) | 24.0% (202/841) | 0.886 |
Ethnicity | ||||
White | % (n/N) | 59.6% (118/198) | 67.0% (549/819) | 0.009 |
Asian | % (n/N) | 16.2% (32/198) | 8.7% (71/819) | |
Black | % (n/N) | 18.7% (37/198) | 20.5% (168/819) | |
Other | % (n/N) | 5.6% (11/198) | 3.8% (31/819) | |
Maternal age at delivery | Mean (SD) | 30.7 (6.0) (n=200) | 28.7 (6.6) (n=830) | <0.001 |
IMD at birth | Mean (SD) | 4.5 (2.7) (n=198) | 4.3 (2.9) (n=824) | 0.287 |
Maternal height | Mean (SD) | 163.0 (6.8) (n=179) | 162.7 (7.0) (n=652) | 0.570 |
Maternal weight | Mean (SD) | 69.1 (16.3) (n=172) | 68.2 (16.5) (n=640) | 0.572 |
Breast milk at any time | % (n/N) | 98.5% (197/200) | 95.7% (794/830) | 0.059 |
Breast milk at discharge | % (n/N) | 56.0% (112/200) | 39.3% (325/828) | <0.001 |
No previous birth ≥24 weeks | % (n/N) | 54.8% (109/199) | 52.5% (434/827) | 0.560 |
Worst cerebral ultrasound scan | % (n/N) | 18.6% (37/199) | 21.6% (179/827) | 0.343 |
Antenatal systemic steroids | % (n/N) | 86.0% (172/200) | 87.7% (718/819) | 0.525 |
Postnatal systemic steroids | % (n/N) | 16.5% (33/200) | 15.0% (125/831) | 0.607 |
Cervical suture | % (n/N) | 8.0% (16/199) | 5.8% (48/830) | 0.236 |
Parenteral nutrition | % (n/N) | 100.0% (200/200) | 99.9% (830/831) | 0.624 |
Days to parenteral nutrition | Median (range) | 1 (0–6) (n=198) | 2 (0–14) (n=830) | 0.116 |
Enteral feeding begun before day 7 | % (n/N) | 87.5% (175/200) | 82.2% (682/830) | 0.070 |
Days to enteral feeding | Median (range) | 3 (0–24) (n=200) | 3 (0–34) (n=830) | 0.006 |
Feeding difficulties at 3 years | % (n/N) | 22.2% (34/153) | 16.1% (68/423) | 0.088 |
Severe neurodevelopment disability at 3 years | % (n/N) | 10.5% (16/153) | 14.4% (61/423) | 0.217 |
*1031 children survived to 3 years, among which 200 children were assessed at 11 years.
IMD, Index of Multiple Deprivation.