Expected and observed percentage (n) below selected centiles: very preterm, late-to-moderate preterm, term: MBRRACE-UK vs UK-WHO (males)
| Expected* | Very preterm (<32 weeks) (n=2724) | Late-to-moderate preterm (32–36 weeks) (n=16 928) | Term (>36 weeks) (n=310 324) | ||||||
| Observed % (n) MBRRACE-UK | Observed % (n) UK-WHO | Risk difference† (95% CI) | Observed % (n) MBRRACE-UK | Observed % (n) UK-WHO | Risk difference† (95% CI) | Observed % (n) MBRRACE-UK | Observed % (n) UK-WHO | Risk difference† (95% CI) | |
| Below 0.4th (0.38%) | 0.40 (11) | 1.10 (30) | 0.70 (0.24 to 1.16) | 0.75 (127) | 0.54 (92) | −0.21 (−0.38 to −0.04) | 0.43 (1346) | 0.21 (638) | −0.23 (−0.26 to −0.20) |
| Below 2nd (2.28%) | 2.90 (79) | 4.70 (128) | 1.80 (0.78 to 2.81) | 2.92 (495) | 2.50 (423) | −0.43 (−0.77 to −0.08) | 1.99 (6163) | 1.21 (3761) | −0.77 (−0.84 to −0.71) |
| Below 9th (9.13%) | 9.40 (256) | 12.00 (327) | 2.60 (0.97 to 4.25) | 9.14 (1548) | 8.48 (1435) | −0.67 (−1.27 to −0.06) | 8.07 (25 029) | 6.08 (18 872) | −1.98 (−2.11 to −1.86) |
| Below 25th (25.24%) | 22.21 (605) | 25.04 (682) | 2.83 (0.57 to 5.08) | 22.89 (3875) | 21.83 (3696) | −1.06 (−1.95 to −0.17) | 23.48 (72 878) | 20.72 (64 302) | −2.76 (−2.97 to −2.56) |
| Below 50th (50%) | 46.99 (1280) | 47.17 (1285) | 0.18 (−2.47 to 2.83) | 48.58 (8223) | 45.79 (7752) | −2.78 (−3.85 to −1.72) | 48.86 (151 631) | 46.28 (143 610) | −2.58 (−2.83 to −2.34) |
| Below 75th (74.76%) | 77.75 (2118) | 74.45 (2028) | −3.30 (−5.57 to −1.04) | 77.07 (13 047) | 73.06 (12 367) | −4.02 (−4.94 to −3.10) | 74.56 (231 374) | 73.47 (227 983) | −1.09 (−1.31 to −0.87) |
| Below 91st (90.87%) | 92.73 (2526) | 89.65 (2442) | −3.08 (−4.59 to −1.58) | 91.62 (15 509) | 88.71 (15 016) | −2.91 (−3.55 to −2.28) | 90.73 (281 547) | 90.30 (280 217) | −0.43 (−0.57 to −0.28) |
| Below 98th (97.72%) | 95.93 (2613) | 94.86 (2584) | −1.06 (−2.18 to 0.05) | 96.82 (16 390) | 95.20 (16 115) | −1.62 (−2.04 to −1.21) | 97.44 (302 393) | 97.29 (301 910) | −0.16 (−0.24 to −0.08) |
| Below 99.6th (99.62%) | 97.03 (2643) | 96.51 (2629) | −0.51 (−1.45 to −0.42) | 98.89 (16 740) | 97.89 (16 570) | 1.00 (−1.27 to −0.74) | 99.44 (308 594) | 99.36 (308 323) | −0.09 (−0.13 to −0.05) |
*Centiles and expected percentages based on 0.67 SD score spacing between centiles.8
†Risk difference=prevalence below a given centile according to UK-WHO minus prevalence according to MBRRACE-UK.