HAS CHANGING DIAGNOSTIC PREFERENCE BEEN RESPONSIBLE FOR THE RECENT FALL IN INCIDENCE OF SUDDEN-INFANT-DEATH-SYNDROME IN SOUTH-AUSTRALIA

Objective: An apparent decrease in deaths attributed to sudden infant death syndrome (SIDS) has been noted in a number of diverse geographic al areas during the past several years. At the same time the definitio n of SIDS has been in a state of flux and some observers have raised t he possibility that the fall in SIDS deaths is due to diagnostic trans fer rather than to a genuine decrease in numbers. The present study wa s undertaken to investigate this possibility. Methodology: All sudden and unexpected deaths in infants under 1 year of age in South Australi a during a 10 year period from 1984 to 1993 were reviewed. Results: Th e number of deaths due to SIDS fell from 40 in 1984 to 17 in 1993, wit h a maximum of 52 cases per year in 1987. In contrast, the number of c ases of sudden death not due to SIDS remained under 10 per year. The o verall infant death rate also fell, while the total number of births p er year remained relatively unchanged. Conclusions: The lack of major change in sudden infant death rates from other causes, combined with t he fall in SIDS deaths, is not supportive of diagnostic transfer being a major determinant of the declining SIDS death rate. Therefore, othe r factors are likely to be responsible for the falling SIDS rate in th is population.