The seasonal distribution of infant deaths by age: a comparison of sudden infant death syndrome and other causes of death.
OBJECTIVE
To examine the possibility that among deaths in infancy the increase in the winter/summer ratio with increasing age is not peculiar to sudden infant death syndrome (SIDS).


METHODS
Details of the winter (December-February)/summer (June-August) ratio among deaths in neonates (< 28 days) and post neonates dying in the United States of America between 1979 and 1990 were abstracted from published statistics. The primary causes of death were classified according to the ninth Revision of the International Classification of Diseases.


RESULTS
For every non-traumatic cause of death including SIDS, the winter/summer ratio was higher among postneonates than neonates. This was not seen for deaths due to trauma. Cases of SIDS and deaths due to infection had the highest ratios in both age categories. Causes of death occurring predominantly in the neonatal period (e.g. anencephaly) had the lowest overall ratios.


CONCLUSIONS
Neither the greater number of SIDS cases in the winter, nor the increasing winter/summer ratio with increasing age is unique to SIDS.
Spiers
P S
PS
Department of Pediatrics, University of Washington Seattle 98195-6320, USA.
Guntheroth
W G
WG
D017677:Age Distribution; D002423:Cause of Death; D006801:Humans; D007223:Infant; D007226:Infant Mortality; D007231:Infant, Newborn; D012621:Seasons; D013398:Sudden Infant Death / Q000453:epidemiology*