Number (percentage) of cases with and without intra-alveolar haemorrhage by risk factors and univariate3-150and multivariate3-151 odds ratios (95% confidence intervals)
| Alveolar haemorrhage | No haemorrhage | Univariate OR (95% CI) | Multivariate OR (95% CI) | |
| Age of infant (weeks) | ||||
| <13 | 32 (64.0) | 18 (36.0) | 4.11 (1.81, 9.36) | 3.57 (1.44, 8.85) |
| 13+ | 16 (30.2) | 37 (69.8) | 1.00 | 1.00 |
| Smoking | ||||
| No | 11 (32.4) | 23 (67.6) | 1.00 | 1.00 |
| Yes | 37 (53.7) | 32 (46.3) | 2.42 (1.02, 5.71) | 1.83 (0.64, 5.24) |
| Position placed to sleep | ||||
| Prone | 17 (31.5) | 37 (68.5) | 0.28 (0.12, 0.63) | 0.40 (0.16, 1.04) |
| Non-prone | 30 (62.5) | 18 (37.5) | 1.00 | 1.00 |
| Position found | ||||
| Prone | 27 (41.5) | 38 (58.5) | 0.43 (0.18, 1.07) | |
| Non-prone | 18 (62.1) | 11 (37.9) | 1.00 | |
| Bed sharing in the last sleep | ||||
| Yes | 28 (68.3) | 13 (31.7) | 4.52 (1.94, 10.53) | 2.21 (0.80, 6.10) |
| No | 20 (32.3) | 42 (67.8) | 1.00 | 1.00 |
↵3-150 Other variables analysed and found not to have any significant relation were region, time of death, season, marital status, age mother left school, age of mother this pregnancy, age of mother first pregnancy, parity, antenatal education, maternal smoking, sex, birth weight, gestation, admission to neonatal unit, breast feeding, dummy usage, illness, thermal insulation.
↵3-151 Multivariate odds ratios control for other variables in the table with the exception of position found.