Table 5.
Increases in neonatal mortality connected with being born in time periods which put infants at risk during the 1918–19 influenza epidemic in Derbyshire: sub-categories of the prematurity, wasting and congenital malformations cause of death examined separately
| Odds ratios associated with periods of birtha | ||
|---|---|---|
| July 1918–Jan. 1919 | Jan.–April 1919 | |
| Prematurity | 1.048 | 1.419 |
| Congenital malformations | 0.540 | 0.767 |
| Wasting | 2.066*** | 2.902*** |
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 hazards analysis, 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.