Overall patient characteristics
| Total | Male | Female | P value | |
| N=55 587 | N=32 379 | N=23 208 | ||
| Gender | <0.001 | |||
| Male | 32 379 (58.2%) | 32 379 (100.0%) | 0 (0.0%) | |
| Female | 23 208 (41.8%) | 0 (0.0%) | 23 208 (100.0%) | |
| Townsend decile at birth | 0.012 | |||
| 1—Least deprived | 3517 (6.3%) | 2072 (6.4%) | 1445 (6.2%) | |
| 2 | 3699 (6.7%) | 2206 (6.8%) | 1493 (6.4%) | |
| 3 | 4223 (7.6%) | 2529 (7.8%) | 1694 (7.3%) | |
| 4 | 4480 (8.1%) | 2607 (8.1%) | 1873 (8.1%) | |
| 5 | 4939 (8.9%) | 2881 (8.9%) | 2058 (8.9%) | |
| 6 | 5392 (9.7%) | 3196 (9.9%) | 2196 (9.5%) | |
| 7 | 6031 (10.8%) | 3529 (10.9%) | 2502 (10.8%) | |
| 8 | 6255 (11.3%) | 3557 (11.0%) | 2698 (11.6%) | |
| 9 | 7042 (12.7%) | 4042 (12.5%) | 3000 (12.9%) | |
| 10—Most deprived | 9323 (16.8%) | 5343 (16.5%) | 3980 (17.1%) | |
| Missing | 686 (1.2%) | 417 (1.3%) | 269 (1.2%) | |
| Maternal age (mean, SD) | 26.71 (5.91) | 26.75 (5.87) | 26.64 (5.97) | 0.021 |
| Maternal age (median, IQR) | 27.00 (22.00–31.00) | 27.00 (22.00–31.00) | 26.00 (22.00–31.00) | 0.007 |
| Maternal age group | 0.10 | |||
| <18 years | 2431 (4.4%) | 1399 (4.3%) | 1032 (4.4%) | |
| 18–24 years | 18 788 (33.8%) | 10 813 (33.4%) | 7975 (34.4%) | |
| 25–29 years | 16 136 (29.0%) | 9496 (29.3%) | 6640 (28.6%) | |
| 30–34 years | 12 269 (22.1%) | 7205 (22.3%) | 5064 (21.8%) | |
| 35+ years | 5852 (10.5%) | 3406 (10.5%) | 2446 (10.5%) | |
| Missing | 111 (0.2%) | 60 (0.2%) | 51 (0.2%) | |
| Gestational age (mean, SD) | 39.25 (2.15) | 39.23 (2.16) | 39.27 (2.12) | 0.067 |
| Gestational age (median, IQR) | 40.00 (38.00–41.00) | 40.00 (38.00–41.00) | 40.00 (38.00–41.00) | 0.21 |
| Gestational age group | 0.016 | |||
| Extreme preterm (<28 weeks) | 134 (0.2%) | 68 (0.2%) | 66 (0.3%) | |
| Very preterm (28–32 weeks) | 766 (1.4%) | 477 (1.5%) | 289 (1.2%) | |
| Moderate or late preterm (33–36 weeks) | 3413 (6.1%) | 2048 (6.3%) | 1365 (5.9%) | |
| Early term (37–38 weeks) | 10 424 (18.8%) | 6097 (18.8%) | 4327 (18.6%) | |
| Full term (39–40 weeks) | 26 018 (46.8%) | 15 026 (46.4%) | 10 992 (47.4%) | |
| Later term (41–42 weeks) | 13 397 (24.1%) | 7828 (24.2%) | 5569 (24.0%) | |
| Post-term (43+ weeks) | 679 (1.2%) | 395 (1.2%) | 284 (1.2%) | |
| Missing | 756 (1.4%) | 440 (1.4%) | 316 (1.4%) | |
| Caesarean section | 0.019 | |||
| No | 47 770 (85.9%) | 27 731 (85.6%) | 20 039 (86.3%) | |
| Yes | 7817 (14.1%) | 4648 (14.4%) | 3169 (13.7%) | |
| Maximum number of injuries | <0.001 | |||
| Total 1 injury-related admission* | 44 539 (80.1%) | 25 608 (79.1%) | 18 931 (81.6%) | |
| Total 2 injury-related admissions | 8453 (15.2%) | 5300 (16.4%) | 3153 (13.6%) | |
| Total 3+ injury-related admissions | 2503 (4.5%) | 1428 (4.4%) | 1075 (4.6%) | |
| Injury-related admission undefined | 92 (0.2%) | 43 (0.1%) | 49 (0.2%) | |
| Number of educational attainment scores across key stages | <0.001 | |||
| One CSI score | 9336 (16.8%) | 5684 (17.6%) | 3652 (15.7%) | |
| Two CSI scores | 28 352 (51.0%) | 16 550 (51.1%) | 11 802 (50.9%) | |
| Three CSI scores | 17 899 (32.2%) | 10 145 (31.3%) | 7754 (33.4%) |
*Same day admissions anomalies but injury was recorded and children were included in analysis (n=28).
CSI, Core Subject Indicator.;