Unit of delivery | 11814 | | 0.001 | | | 0.0003 |
Hospital 1 | 101/3222 | 1 | | 89/3076 | 1 | |
Hospital 2 | 65/1765 | 1.17 (0.86 to 1.61) | | 61/1747 | 1.25 (0.90 to 1.74) | |
Hospital 3 | 55/841 | 2.09 (1.49 to 2.92) | | 45/743 | 2.31 (1.59 to 3.35) | |
Hospital 4 | 91/2484 | 1.17 (0.88 to 1.56) | | 77/2327 | 1.42 (1.03 to 1.97) | |
Hospital 5 | 96/3094 | 0.99 (0.75 to 1.31) | | | –‡ | |
Mode of delivery | 11798 | | 0.38 | | | |
Normal vaginal | 298/8620 | 1 | | 207/5928 | | |
Assisted vaginal | 41/1415 | 0.84 (0.60 to 1.17) | | 29/1069 | | |
Caesarean section | 53/1371 | 1.12 (0.83 to 1.51) | | 33/896 | | |
Gestation (weeks) | 8571 | | <0.0001 | | | 0.001 |
35–37 | 57/596 | 1.92 (1.42 to 2.59) | | 37/542 | 1.72 (1.15 to 2.57) | |
38–40 | 260/5213 | 1 | | 178/5054 | 1 | |
>40 | 74/2371 | 0.63 (0.48 to 0.81) | | 57/2297 | 0.70 (0.51 to 0.95) | |
Parity | 7678 | | 0.13 | | | |
Primiparous | 167/3459 | 0.85 (0.69 to 1.05) | | 112/3253 | | |
Multiparous | 217/3835 | 1 | | 148/3677 | | |
Maternal age (years) | 11794 | | 0.96 | | | |
<20 | 53/1444 | 1.10 (0.79 to 1.52) | | 30/982 | | |
20–24 | 90/2569 | 1.05 (0.79 to 1.38) | | 65/1720 | | |
25–29 | 117/3493 | 1 | | 87/2440 | | |
30–34 | 89/2665 | 1.00 (0.75 to 1.32) | | 60/1906 | | |
>35 | 39/1235 | 0.94 (0.65 to 1.36) | | 29/845 | | |
Birth weight | 8704 | | <0.0001 | | | 0.05 |
<2500 g | 36/295 | 2.71 (1.89 to 3.89) | | 20/237 | 1.95 (1.16 to 3.28) | |
2500–4499 g | 355/7876 | 1 | | 249/7525 | 1 | |
>4499 g | 4/138 | 0.64 (0.24 to 1.75) | | 3/131 | 0.75 (0.24 to 2.40) | |
Feeding at hospital discharge | 8522 | | 0.004 | | | 0.007 |
Formula | 247/4681 | 1 | | 183/4564 | 1 | |
Breast | 127/3370 | 0.71 (0.57 to 0.89) | | 88/3242 | 0.69 (0.53 to 0.90) | |
Mixed | 2/95 | 0.40 (0.10 to 1.63) | | 1/87 | 0.27 (0.04 to 1.97) | |
Deprivation quintile | 11648 | | 0.03 | | | |
1 | 65/2264 | 1 | | 52/1779 | | |
2 | 60/2251 | 0.93 (0.65 to 1.33) | | 39/1552 | | |
3 | 73/2255 | 1.13 (0.80 to 1.58) | | 55/1511 | | |
4 | 82/2241 | 1.27 (0.92 to 1.77) | | 58/1477 | | |
5 | 97/2260 | 1.49 (1.09 to 2.06) | | 68/1574 | | |
Early discharge | 11721 | | 0.01 | | | |
No | 249/6595 | 1 | | 169/4515 | | |
Yes | 134/4743 | 0.75 (0.60 to 0.93) | | 103/3378 | | |