The number and percent of cases and controls for each factor, percent missing data, univariate ORs and Cls based on complete data. Also, univariate ORs and multivariate AORs and Cls based on the imputed data sets.
| Cases | Controls | Percentage of missing | Complete records Single factor | Complete and imputed data Single factor Selected multivariate | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Variable | No | % | No | % | records | OR | 95% CI | OR* | 95% CI | AOR‡ | 95% CI |
| Bed sharing No Yes | 1131 323 | 77.8 22.2 | 4192 446 | 90.4 9.6 | 0.9 | 1 2.6 | 2.2 to 3.1 | 1 2.6 | – 2.2 to 3.1 | 1 2.7‡ | – 1.4 to 5.3 |
| Feeding Breast Bottle | 504 940 | 34.9 65.1 | 2491 2168 | 53.5 46.5 | 0.8 | 1 2.9 | – 2.5 to 3.3 | 1 2.9 | – 2.5 to 3.3 | 1 1.5 | – 1.2 to 1.8 |
| Position last left Back all ages Side Front | 377 438 607 | 26.5 30.8 42.7 | 1972 1869 791 | 42.6 40.3 17.1 | 1.6 | 1 1.6 7.8 | – 1.3 to 1.8 6.4 to 9.5 | 1 1.6 7.9 | – 1.3 to 1.9 6.5 to 9.6 | 1 1.5† 10.5† | – 1.2 to 2.1 7.5 to 14.6 |
| Parental smoking Neither Partner only Mother only Both | 314 194 194 703 | 22.4 13.8 13.8 50.0 | 2285 1083 427 774 | 50.0 23.7 9.4 16.9 | 2.9 | 1 1.4 3.7 7.4 | – 1.1 to 1.7 3.0 to 4.6 6.2 to 8.7 | 1 1.4 3.8 7.3 | – 1.1 to 1.7 3.1 to 4.7 6.2 to 8.6 | 1 1.1* 1.5* 2.9* | – 0.8 to 1.4 1.2 to 2.1 2.3 to 3.6 |
| Mother took 2 unit or more of alcohol in last 24 h | 61.3 | ||||||||||
| No Yes | 478 112 | 81.0 19.0 | 1694 99 | 94.5 5.5 | 1 5.1 | – 3.7 to 7.0 | 1 6.5 | – 4.6 to 9.3 | 1 4.8* | – 2.6 to 8.9 | |
| Mother used illegal drugs after birth | 60.5 | ||||||||||
| None Any | 582 21 | 96.5 3.5 | 1825 3 | 99.8 0.2 | 1 19.2 | – 5.4 to 68.3 | 1 30.7 | – 8.8 to 106.8 | 1 11.5* | – 2.2 to 59.5 | |
| Sex Unmatched studies: Female Male | 351 538 | 39.5 60.5 | 1401 1442 | 49.3 50.7 | 0.3 | 1 1.5 | – 1.3 to 1.8 | 1 1.5 | – 1.3 to 1.7 | 1 1.6 | – 1.3 to 1.9 |
| Matched studies: Female Male | 217 360 | 37.6 62.4 | 683 1141 | 37.5 62.5 | 1 1.0 | – 0.8 to 1.2 | 1 1.0 | – 0.8 to 1.2 | 1 0.8 | – 0.6 to 1.1 | |
| Race White Non-white | 1181 276 | 81.1 18.9 | 4242 434 | 90.7 9.3 | 0.3 | 1 3.0 | – 2.5 to 3.6 | 1 3.0 | – 2.5 to 3.6 | 1 1.5 | – 1.1 to 1.9 |
| Birth Weight group: 3500 g or more 2500 to 3499 g 2000 to 2499 g under 2000 g | 415 760 144 120 | 28.9 52.8 10.0 8.3 | 2293 2092 127 59 | 50.1 45.8 2.8 1.3 | 2.3 | 1 2.0 6.3 13.5 | – 1.7 to 2.3 4.8 to 8.2 9.6 to 18.9 | 1 2.0 6.4 13.8 | – 1.7 to 2.3 4.9 to 8.3 9.8 to 19.4 | 1 1.7 4.2 9.6 | – 1.4 to 2.0 2.9 to 6.0 6.2 to 14.7 |
| Mother's age in years Over 30 26 to 30 21 to 25 19 to 20 18 under | 326 419 434 162 113 | 22.4 28.8 29.9 11.1 7.8 | 1921 1552 910 169 111 | 41.2 33.3 19.5 3.6 2.4 | 0.6 | 1 1.8 3.3 6.8 7.1 | – 1.5 to 2.1 2.8 to 3.9 5.2 to 8.8 5.3 to 9.6 | 1 1.8 3.3 6.8 7.2 | – 1.5 to 2.1 2.8 to 3.9 5.3 to 8.8 5.3 to 9.7 | 1 1.9 3.0 7.7 9.1 | – 1.5 to 2.3 2.4 to 3.8 5.2 to 11.4 5.9 to 14.1 |
| Number of live births including the present one: | 0.8 | ||||||||||
| 1 2 3 4 5 or more | 407 491 280 149 122 | 28.1 33.9 19.3 10.3 8.4 | 1836 1566 748 304 200 | 39.4 33.7 16.1 6.5 4.3 | 1 1.4 1.8 2.6 3.5 | – 1.2 to 1.7 1.5 to 2.2 2.1 to 3.3 2.7 to 4.5 | 1 1.4 1.9 2.6 3.5 | – 1.2 to 1.7 1.5 to 2.2 2.1 to 3.3 2.7 to 4.6 | 1 2.3 3.8 5.2 7.7 | – 1.9 to 2.9 2.9 to 4.9 3.7 to 7.4 5.3 to 11.3 | |
| Mother's marital status: Married or with partner Single | 996 467 | 68.1 31.9 | 4049 628 | 86.6 13.4 | 0.2 | 1 4.0 | – 3.4 to 4.7 | 1 4.0 | – 3.4 to 4.7 | 1 1.9 | – 1.5 to 2.4 |
| Where slept last Parents' room Elsewhere | 817 617 | 56.9 43.1 | 2806 1823 | 60.6 39.4 | 1.4 | 1 1.3 | – 1.1 to 1.5 | 1 1.3 | – 1.2 to 1.5 | 1 2.4 | – 2.0 to 2.9 |
‡Multivariate AORs including AOR for bed sharing pooled for all ages up to 1 year. †Multivariate AOR when baby in a cot in parent's room & age is 3 months or less. The corresponding AOR's when baby is over 3 m are 1.4 (1.1 to 1.8) & 7.7 (5.9 to 10.2) respectively. *Multivariate AOR when baby in a cot in parents' room. AOR, Adjusted OR.