THe changing seasonality of infant deaths in England and Wales 1912-78 and its relation to seasonal temperature.

Abstract

Seasonal variation in the rates of stillbirth and of deaths under the age of 1 yr were studied for England and Wales to examine changes in the seasonal variation over the years and the correlation between seasonal rates and seasonal temperatures. The quarterly rates of stillbirths were studied for the period 1928-1978 and of deaths under the age of 1 yr, in 6 different age groups, for the period 1912-1978. A disappearance of seasonal variation in rates (deseasonality) occurred for stillbirths in .apprx. 1950, and for neonatal deaths in .apprx. 1965. For deaths at 1-2 mo. a trend towards deseasonality was apparent since 1955, but there was no such trend for deaths at 3-11 mo. of age. In the period before deseasonality, and for the 1st quarter of the year, there was a high negative correlation between the neonatal death rate and the mean temperature in England and Wales but this correlation fell as the seasonal variation in rates fell. Seasonal variation in the neonatal death rate apparently was closely related to winter temperatures during the period 1921-1960. For deaths at 1-11 mo. old, there was and still is a relation between temperature and seasonal variation in rates, but the relation was less close than for the neonatal death rate.