Inaccurate classification of infant deaths in Australia: a persistent and pervasive problem

There have also been numerous initiatives in Australia and worldwide to improve our ability to distinguish between SIDS and other causes of unexpected infant death. These initiatives include attempts to standardise the definition of SIDS and to introduce uniform guidelines for evaluation of death scenes and autopsy examinations. Unfortunately, significant problems persist. SIDS remains a diagnosis of exclusion, with no pathognomonic features at autopsy. Causes of death such as poisoning, or accidental or deliberate asphyxia, may appear to the pathologist identical to SIDS, and cardiovascular diseases, occult infections and metabolic disorders may be identified only by special dissections or investigations. The confusion that arises with individual pathologists' choosing different definitions is reflected in the recent international literature, where deaths have been accepted as SIDS in the apparent absence of recognised formal definitions. In addition, there is no consistency in the definition of SIDS being used by clinicians, researchers or pathologists in Australia.

A number of different definitions of SIDS have been promulgated over the past decade, each emphasising a different aspect: for example, an association with sleep; a requirement for extensive ancillary postmortem investigations (eg, microbiological and toxicological testing); subclassifications based on the presence or absence of minor pathological findings; and specified upper and lower age limits.^1-5

There is also an urgent need for a standardising of the investigation of unexpected infant deaths, including guidelines for reviewing the clinical and family history, for carefully examining the death scene and for conducting the autopsy according to established criteria. Established autopsy criteria have included full-body radiological examination and microbiological and toxicological testing. Despite the availability of standard investigative protocols for infant deaths (Box), no protocol is consistently applied in Australia. The usefulness of protocols has been clearly established: more deaths due to unsafe sleeping environments have been identified recently, and each step of the postmortem investigation has been shown to contribute potentially significant information.^9,10

Failure to implement a standard approach to unexpected infant deaths may cause distress for families who subsequently discover that significant steps were missed in the autopsy evaluation of their infant. It may also have far-reaching consequences. In the United Kingdom, 42 deaths originally attributed to SIDS were found to be due to homicides.¹¹ The initial failure to diagnose these as homicides would have interfered with police investigations and may have endangered other children in these families and allowed the perpetrators to escape punishment. Australian courts have also reached the same conclusions in similar retrospectively reviewed cases.

Recent infant deaths in rural Australia have been accepted as SIDS without proper death scene examinations or autopsies.¹² An investigation of autopsy practices in Queensland by a Working Group of the Queensland Council on Obstetric and Paediatric Morbidity and Mortality confirmed that major problems exist, particularly in rural areas.¹³ The group found that 65% of the reviewed autopsies in infants who died suddenly and unexpectedly failed to attain the minimum acceptable quality score set by the study. They concluded that these autopsies were of "poor quality" and that "a specialist pathologist with appropriate expertise" was required. Similar conclusions were reached in an inquest into a series of infant deaths in South Australia.¹⁴ Thus, we have an unacceptable situation: diagnostic guidelines are readily available but are not being used. This is partly because of isolation in rural Australia and underfunding of services.

In isolated regions of Australasia infant autopsies have also been performed by non-pathologists. Infant autopsy examination is highly specialised, requiring specific dissection techniques and considerable knowledge of both paediatric and forensic pathology. Expecting non-specialists to perform infant autopsies is neither appropriate nor fair and makes the validity of some of the autopsy conclusions uncertain.

It is time to undertake a national initiative to correct these deficiencies. Details of these problems were presented at a national meeting of forensic pathologists in Perth in June this year, with a proposal to convene a National Workshop of Pathologists, in association with SIDSaustralia, to choose an appropriate definition for SIDS and investigative guidelines. It is hoped that these conclusions could be evaluated and endorsed by the Forensic Committee of the Royal College of Pathologists of Australasia and appropriate national "gold standards" agreed upon. Then pathologists' concerns and consensus recommendations for change could be passed on to the respective coronial authorities to ensure proper medicolegal investigation of unexpected infant deaths. Implementing these guidelines would not be easy, requiring financial support by governments, coordinated training programs and local cooperation, and possibly legislative changes in some States.

A recently established national coronial database will enable the monitoring of trends in unexpected death in Australia.¹⁵ However, idiosyncratic or inexact diagnostic practices among pathologists and failure to follow protocols will result in inaccurate statistics on infant deaths in Australia. This could lead to underdiagnosis of important diseases and conditions, and unreliability of research based on these data. Opportunities to save more lives will be lost, parents will be ill-informed, and coroners will not have a clear picture of problems within their jurisdictions. Over a decade ago, the late John Emery raised the spectre of SIDS becoming a "diagnostic dustbin"¹⁶ — unfortunately, he may well have been correct.

Roger W Byard
Specialist Forensic Pathologist, Forensic Science Centre, Adelaide, SA;
Clinical Professor, Departments of Paediatrics and Pathology
University of Adelaide, Adelaide, SA
byard01ATforensic.sa.gov.au

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