Table 2.
Increases in mortality connected with being born in time periods which put infants at risk during the 1918–19 influenza epidemic in Derbyshire: stillbirths, neonatal mortality and post-neonatal mortality examined separately
| Period of birth | Odds ratioa | |
|---|---|---|
| Stillbirth | July 1918–April 1919 | 1.247* |
| Sept. 1918–Jan. 1919 | 1.535*** | |
| Neonatal mortality | July 1918–April 1919 | 1.326** |
| Jan. 1919–April 1919 | 1.776*** | |
| Post neonatal mortality | 1918 | 1.500*** |
| Feb. 1918 | 1.668* | |
| July 1918–Sept. 1918 | 1.935*** |
a
Odds ratios give the multiplicative increase in mortality associated with period of birth, compared to a value of 1.000 for all other months in the period 1917–22. Each odds ratio is derived from a separate multivariate analysis (logistic analyses in the case of stillbirths, and hazards analyses for neonatal and post-neonatal mortality), in which other variables are also controlled (see text for details).
***
Significant at 1% level.
**
Significant at 5% level.
*
Significant at 10% level.
Source: Derbyshire health visitor data.