A study of the sudden infant death syndrome by age.

Data from 201 infants in South East Scotland certified at death as sudden infant death syndrome (SIDS) were analysed to determine whether the cases in the younger age groups at death (4-19 weeks) differed from those in the older group (19-52 weeks) on a number of background, developmental and medical variables frequently associated with SIDS in research findings. Some of the findings of the study were contrary to much of the research on SIDS in general. While some factors commonly associated with SIDS were found in both groups the 'typical' pattern presented in SIDS in the literature was more strongly associated with the older group. Marked differences between the two age groupings at death raise questions concerning those aspects of causation and aetiology that may go undetected if this distinction is not made during the analysis of SIDS information.