Odds ratios (OR*) of more severe versus mild cases by Z-score band
| Z-score band | Overall proportion more severe | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Equivalent centiles: | <−1.88 <3% OR (n†) | −1.88 to <−1.28 3 to <10% OR (n) | −1.28 to <−0.67 10 to <25% OR (n) | −0.67 to <0 25 to <50% OR (n) | 0 to <0.67 50 to <75% OR (n) | 0.67 to <1.28 75 to <90% OR (n) | 1.28 to <1.88 90 to <97% OR (n) | ⩾1.88 ⩾97% OR (n) | |
| *Odds ratio by comparison to the reference band 0.67 to <1.28 Z-score. Bold, p < 0.01. | |||||||||
| †n = more severe + mild cases (for n more severe cases only see table 1). For instance, the OR for being a more severe rather than a mild case (all gestations) with a birth weight Z-score <−1.88 is (271/(532–271))/(101/(249–101)) = 1.52 [99% CI 1.02 to 2.27]. | |||||||||
| All gestations | 1.5 (532) | 1.7 (404) | 1.2 (584) | 1.2 (611) | 1.3 (476) | 1 (249) | 1.4 (135) | 1.5 (131) | 0.48 |
| Preterm | 1.4 (247) | 1.4 (157) | 1.1 (223) | 1.1 (259) | 1.2 (179) | 1 (87) | 1.2 (54) | 1.4 (59) | 0.52 |
| Term | 1.6 (285) | 1.8 (247) | 1.3 (361) | 1.2 (352) | 1.4 (297) | 1 (162) | 1.5 (81) | 1.4 (72) | 0.45 |
| Bilat spastic | 1.3 (390) | 1.3 (277) | 1.4 (354) | 1.2 (371) | 1.5 (257) | 1 (143) | 1.2 (81) | 1.3 (77) | 0.65 |
| Hemiplegic | 1.6 (144) | 2.9 (108) | 1.4 (184) | 1.4 (197) | 1.4 (168) | 1 (87) | 1.9 (40) | 1.4 (33) | 0.10 |
| Males | 1.7 (328) | 1.9 (239) | 1.5 (328) | 1.3 (348) | 1.4 (286) | 1 (134) | 1.4 (65) | 1.6 (75) | 0.47 |
| Females | 1.4 (204) | 1.4 (165) | 1.0 (256) | 1.2 (263) | 1.3 (190) | 1 (115) | 1.3 (70) | 1.3 (56) | 0.49 |
| More severe intellectual impairment (IQ <50) | |||||||||
| All gestations | 1.5 (540) | 1.6 (414) | 1.3 (591) | 1.1 (618) | 1.2 (480) | 1 (251) | 1.3 (137) | 1.1 (135) | 0.28 |
| Walking impairment (not walking independently) | |||||||||
| All gestations | 1.4 (730) | 1.3 (510) | 1.1 (738) | 1.1 (802) | 1.2 (658) | 1 (345) | 1.3 (197) | 1.2 (203) | 0.45 |