Combined effect of infants small at birth and infant sleeping position
| SIDS | Controls | Univariate* | Multivariate† | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| n | (%) | n | (%) | OR (95% CI) | p value‡ | p value§ | OR (95% CI) | p value‡ | p value§ | ||
| *Adjusted for infant age in a conditional logistic regression model. | |||||||||||
| †Adjusted for infant age, birth centile, higher parity, parental unemployment, moving house more than once in the last year, young maternal age, maternal smoking during pregnancy, postnatal exposure to tobacco smoke, any episode of lifelessness, and for the last sleep: change in usual routine, recent infant illness, lack of recent sleep, recent maternal alcohol consumption, bed sharing, sofa sharing, sleeping outside the parental bedroom, using a dummy, bedding and clothes higher than 10 tog, and found with head covered by bedding. | |||||||||||
| ‡p value relates to the significance of the combined effect of the odds ratio. | |||||||||||
| §p value relates to the interactions of positioned side × being small at birth and positioned prone × being small at birth. | |||||||||||
| Position put down | Small at birth | ||||||||||
| Back | No | 111 | (35.2) | 815 | (63.6) | 1.00 (ref group) | 1.00 (ref group) | ||||
| Side | No | 89 | (28.3) | 329 | (25.7) | 2.02 (1.44 to 2.84) | <0.0001 | 2.27 (1.25 to 4.11) | 0.007 | ||
| Front | No | 33 | (10.5) | 36 | (2.8) | 9.29 (5.08 to 17.01) | <0.0001 | 8.09 (2.60 to 25.13) | 0.0003 | ||
| Back | Yes | 29 | (9.2) | 73 | (5.7) | 2.98 (1.73 to 5.12) | <0.0001 | 4.63 (1.58 to 13.55) | 0.005 | ||
| Side | Yes | 39 | (12.4) | 26 | (2.0) | 9.13 (4.93 to 16.90) | <0.0001 | 0.37 | 14.96 (5.10 to 43.93) | <0.0001 | 0.77 |
| Front | Yes | 14 | (4.4) | 2 | (0.2) | 62.81 (12.06 to 327.12) | <0.0001 | 0.33 | 24.37 (2.42 to 245.26) | 0.007 | 0.58 |
| Position found | Small at birth | ||||||||||
| Back | No | 86 | (28.3) | 948 | (76.8) | 1.00 (ref group) | 1.00 (ref group) | ||||
| Side | No | 51 | (16.8) | 115 | (9.3) | 5.01 (3.13 to 8.01) | <0.0001 | 7.20 (2.98 to 17.39) | <0.0001 | ||
| Front | No | 86 | (28.3) | 72 | (5.8) | 22.50 (12.95 to 39.09) | <0.0001 | 47.19 (14.52 to 153.40) | <0.0001 | ||
| Back | Yes | 30 | (9.9) | 81 | (6.6) | 4.58 (2.57 to 8.17) | <0.0001 | 5.22 (1.58 to 17.20) | 0.007 | ||
| Side | Yes | 23 | (7.6) | 16 | (1.3) | 10.92 (4.95 to 24.12) | <0.0001 | 0.14 | 37.41 (7.74 to 180.70) | <0.0001 | 0.45 |
| Front | Yes | 28 | (9.2) | 3 | (0.2) | 186.07 (38.50 to 899.29) | <0.0001 | 0.49 | 139.63 (16.78 to 1162.16) | <0.0001 | 0.36 |