| Study Population | Low-riskc | Healthy controlsd | From 1 July 2007e | Primaryf | 1-yearg | 2-yearh |
---|---|---|---|---|---|---|---|
Study population (N) | 893,360 | 435,417 | 610,538 | 387,539 | 893,360 | 893,360 | 893,360 |
Children admitted (%) | 4.6 | 4.6 | 6.8 | 2.3 | 4.1 | 1.6 | 3.0 |
 | aHR (95 % CI) | aHR (95 % CI) | aHR (95 % CI) | aHR (95 % CI) | aHR (95 % CI) | aHR (95 % CI) | aHR (95 % CI) |
Mode of birth | Â | Â | Â | Â | Â | Â | Â |
Vaginal birth – spontaneous onset of labour | 1.00 [Reference] | 1.00 [Reference] | 1.00 [Reference] | 1.00 [Reference] | 1.00 [Reference] | 1.00 [Reference] | 1.00 [Reference] |
Vaginal birth – labour induction | 1.12 (1.09–1.15) | 1.12 (1.08–1.16) | 1.15 (1.12–1.18) | 1.10 (1.04–1.16) | 1.13 (1.10–1.16) | 1.18 (1.13–1.23) | 1.14 (1.10–1.17) |
Caesarean section – pre-labour | 1.19 (1.16–1.23) | 1.17 (1.11–1.22) | 1.24 (1.20–1.27) | 1.20 (1.13–1.27) | 1.20 (1.16–1.23) | 1.24 (1.18–1.31) | 1.22 (1.17–1.26) |
Caesarean section – spontaneous onset of labour | 1.20 (1.16–1.25) | 1.15 (1.08–1.22) | 1.24 (1.20–1.29) | 1.22 (1.13–1.33) | 1.21 (1.16–1.26) | 1.25 (1.17–1.34) | 1.24 (1.18–1.30) |
Caesarean section – labour induction | 1.23 (1.18–1.29) | 1.31 (1.22–1.41) | 1.28 (1.22–1.34) | 1.18 (1.07–1.29) | 1.23 (1.17–1.29) | 1.33 (1.23–1.43) | 1.26 (1.20–1.33) |
Gestational age (weeks) | Â | Â | Â | Â | Â | Â | Â |
33–36 | 1.23 (1.18–1.29) | - | 1.44 (1.37–1.50) | 1.28 (1.16–1.40) | 1.23 (1.17–1.29) | 1.28 (1.19–1.38) | 1.24 (1.17–1.31) |
37–38 | 1.15 (1.12–1.17) | 1.14 (1.10–1.19) | 1.21 (1.18–1.24) | 1.17 (1.11–1.23) | 1.14 (1.11–1.17) | 1.19 (1.15–1.24) | 1.15 (1.12–1.19) |
39–42 | 1.00 [Reference] | 1.00 [Reference] | 1.00 [Reference] | 1.00 [Reference] | 1.00 [Reference] | 1.00 [Reference] | 1.00 [Reference] |
Formula-only feedingb | 1.18 (1.11–1.24) | 1.17 (1.08–1.26) | 1.19 (1.14–1.25) | 1.20 (1.14–1.28) | 1.17 (1.11–1.24) | 1.34 (1.25–1.44) | 1.24 (1.17–1.31) |