Infant characteristics by region of care
| California | Massachusetts | United Kingdom | Total | p Value | |
|---|---|---|---|---|---|
| p Value indicates whether the distribution of each infant characteristic differs significantly across region of care. | |||||
| na, Not available. | |||||
| Number of infants | 390 | 460 | 3509 | 4359 | |
| Mother received antenatal steroids | |||||
| Yes/total | 259/387 | 305/460 | 2285/3485 | 2849/4332 | 0.839 |
| Percentage | 66.9 | 66.3 | 65.6 | 65.8 | |
| Delivered by caesarean section | |||||
| Yes/total | 223/390 | 269/460 | 1988/3508 | 2480/4358 | 0.758 |
| Percentage | 57.2 | 58.5 | 56.7 | 56.9 | |
| Gestational age at delivery (weeks) | |||||
| Mean (SD) | 32.8 (1.3) | 32.7 (1.3) | 32.7 (1.3) | 32.7 (1.3) | 0.280 |
| Sex of infant | |||||
| Male/total | 193/390 | 236/460 | 1862/3508 | 2291/4358 | 0.342 |
| Percentage | 49.5 | 51.3 | 53.1 | 52.6 | |
| Birth weight (g) | |||||
| Median (25th, 75th centile) | 1885 (1615, 2191) | 1975 (1670, 2237) | 1905 (1619, 2200) | 1910 (1622, 2200) | 0.009 |
| Apgar score at 5 min | |||||
| Median (25th, 75th centile) | 9 (8, 9) | 9 (8, 9) | 9 (9, 10) | 9 (8, 9) | <0.001 |
| Infant received mechanical ventilation | |||||
| Yes/total | 89/390 | 136/460 | 936/3484 | 1161/4334 | 0.084 |
| Percentage | 22.8 | 29.6 | 26.9 | 26.8 | |
| Postmenstrual age at discharge (weeks) | |||||
| Mean (SD) | 35.9 (1.3) | 36.3 (1.3) | 36.3 (1.9) | 36.2 (1.8) | <0.001 |
| Maternal race | |||||
| White/total | 109/306 | 296/367 | na | 405/673 | <0.001 |
| Percentage | 26.9 | 73.1 | 60.2 | ||
| Family income | |||||
| Income >$50 000/total | 204/306 | 317/370 | na | 521/676 | <0.001 |
| Percentage | 66.7 | 85.7 | 77.1 | ||
| Maternal education | |||||
| Graduated from high school/total | 229/305 | 313/370 | na | 542/675 | 0.002 |
| Percentage | 75.1 | 84.6 | 80.3 | ||
| Index of multiple deprivation | |||||
| Median (25th, 75th centile) | na | na | 22.3 (14.6, 34.4) | ||