The 1969 definition of SIDS by Beckwith and colleagues has benefited innumerable families and been a focus for research that has culminated in "typical" SIDS becoming a rarity in many countries. This welcome reduction in SIDS cases has brought to the forefront problems with the definition and its overuse.
Problems arise because the definition (which is really a description) is imprecise and because the term SIDS is used in 2 different and sometimes incompatible ways. First, it is a certifiable cause of death that is also a starting point for supporting bereaved parents; second, it is an inclusion criterion for SIDS research. This dichotomy is addressed in Dr Beckwith's proposed 2-tier approach, but the imprecision is not.
Berry PJ. SIDS: Permissive or Privileged "Diagnosis"?. Arch Pediatr Adolesc Med. 2003;157(3):293-294. doi:10.1001/archpedi.157.3.293