[Incidence and regression of sudden infant death in Austria. Is the change in the SIDS incidence real or virtual?].

After the rise in incidence of the sudden infant death syndrome (SIDS) in the 1980s to a peak of 1.7/1000 live births in Austria in 1988, the SIDS rate more than halved to 0.79/1000 live births in 1994. This trend can be regarded as typical of the epidemiology of SIDS in most Western countries. It is commonly interpreted as a result of preventive measures. However, the decline in incidence of SIDS started several years before systematic preventive activities were undertaken in Austria. Graphical presentation shows that the dynamics of SIDS does not affect the almost linear decline in postneonatal mortality over the past 25 years, as would be expected from the fact that SIDS is the most important cause of death in the postneonatal period. A comparative analysis of trends of postneonatal SIDS and non-SIDS mortality reveals that in Austria the increase of SIDS was accompanied by a rapid fall of non-SIDS mortality, whereas, on the contrary, the decline of SIDS went along with relative increase of non-SIDS mortality. Changing awareness of coroners and forensic pathologists of SIDS, with the resultant changes in frequency and performance of postmortem examinations, and changes in coding practices of causes of death should be taken into consideration as determinants of SIDS incidence before interpreting trends as resulting from public health interventions.