The increase of PubMed citations about SIDS from only 157 before 1976 to 5542 on September 9, 2002, illustrates the dramatic accumulation of knowledge about SIDS. However, certain SIDS characteristics, such as unique age distribution and apparent relationship to sleep, that have been documented repeatedly since the earliest descriptions still have not been incorporated into its definition. In fact, the only alteration in the SIDS definition between 1969 and 1989 has been the incorporation of "examination of the death scene," which, in reality, was occurring at some level all along. Therefore, Beckwith's proposed refinement of the SIDS definition into 2 tiers for purposes of administration and death certification as well as research and statistics is timely. Furthermore, as he noted, widespread implementation of infant care practices that have reduced the number of SIDS deaths has led to cases coming disproportionately from lower socioeconomic groups with chaotic backgrounds; such cases are often more difficult to diagnose.
Krous HF. Reflections on Redefining SIDS. Arch Pediatr Adolesc Med. 2003;157(3):291-292. doi:10.1001/archpedi.157.3.291