Suddeninfant deathsyndrome insouth eastScotland

SUMMARY Threehundred andfifty eight infants fromsoutheastScotland whodiedsuddenly were classified into four groups.Categories forthese groupsranged fromwhereadefinite cause ofdeathhadbeenrecorded towhereno explanation hadbeenprovided andno associated disorder was discovered (SIDS). Ourresults supported theviewthat there arefewdifferences in thehistory ofcasescertified asSIDSandother casesreported asdyingsuddenly butwithan explanation. Groupsthat mostclosely matched theSIDSdefinition employed were reported to behealthier throughout life andfreer fromillness inthe48hours before death. Fromthefindings ofthis study the'true' SIDSgroup didnotappearasan 'atrisk' population. Thestudy groupasa whole was notmarkedbysocial deprivation, poor mothering, or less privileged families. The importance ofintensive investigation, including postmortemexamination was emphasised, as misdiagnosis may give a'falsely' inflated picture oftheincidence ofthesyndrome andcould cause unnecessaryanxiety. A definition commonlyemployed intheidentificationofinstances ofthesuddeninfant deathsyndrome(SIDS) isthatproposed inSeattle in1969: "Thesuddendeathofanyinfant oryoungchild whichisunexpected byhistory, andinwhicha thorough post-mortem examination fails toreveal anadequate causeofdeath."' Inthis study datafromagroupofinfants whodied suddenly andunexpectedly andwhopresented as cases ofSIDSwereanalysed todetermine towhat extent theymatched theabovedefinition andto study anydifferences detected. Thecriterion forthediagnosis ofSIDSwas necessarily pathological aseachinfant's death was unexpected byhistory. Tocarry outthis investigationandenable discrimination between thepathological findings, fourcategories ofclassification wereemployed. Theseclassifications, A,AB,B, andC,enabled analysis ofthevarious findings and studyoftheextent towhicheachmay have contributed tothedeath. Thevariables usedasparameters forcomparison between thegroups wereselected onthebasis of their citation inreviews that dealt withSIDSwhere possible riskfactors, suchaspreterm delivery, mother's agelessthan20years, andpoorsocial conditions surrounding thefamily, havebeen indicated.2 3