Suicide in South Australia: specific features, trends and reasons for disparities in numbers

Suicide constitutes a significant and yet under-recorded component of preventable mortality in many communities. Prevalent methods of suicide vary over time, and are influenced by the availability of noxious agents as well as ideas of what constitutes lethal techniques. Despite indications of self-destructive acts in many instances, it is sometimes difficult to accurately designate the manner of death as suicide, resulting in misclassifications among individual records. For example, deaths due to drug overdose, a fall from a height and drowning may be ‘accidental’, intentional or homicidal. Such ambiguities are carefully considered in forensic medicolegal investigations, through integration of death scene and autopsy findings. Thus, single forensic centres that service an explicit geographical area and have direct access to case information may produce more valid suicide data than larger and less specific national registers which rely upon records that may be incomplete or inaccurate. The following study was undertaken to examine suicide among medicolegal deaths in South Australia, to compare this with South Australian data on national registers and to delineate the characteristics of such cases. A manual and electronic search was undertaken of pathology files at Forensic Science SA in Adelaide, Australia, for cases of suicide. All cases had undergone full police and coronial investigations. Case details were examined and the sex, age and race of victims, as well as reports on toxicology, the circumstances of death and/or means of suicide were collated. Significant changes in the sex-, age- and method-specific patterns of suicide over recent years were identified. Specifically, there was a general decline in the rates of male suicides although, no statistically significant changes were observed in the registered rates for females. Available data from national registers were also reviewed from the National Coronial Information System and from the Australian Bureau of Statistics. After separating victims by sex, an overall under-reporting of suicides of 5.4% of local male cases as well as 13.5% of local female cases in the National Coronial Information System, and of 4.9% of local male cases as well as 14.0% of local female cases by the Australian Bureau of Statistics, was recorded, with a progressive increase in differences between reported numbers of suicides over time and particularly in recent years. Also, when cases were sub-classified according to the method used or specific groups of victims, further trends were discerned over time, including a decrease in overall deaths by carbon monoxide inhalation and male hangings, whereas hangings preponderated among Aboriginal as well as incarcerated people in South Australia. Additionally, overall drug-related deaths, asphyxial deaths using helium and female hangings, all showed increases compared to previous years. This study has demonstrated that despite a modest decline in the overall rate of suicide in South Australia, there have been marked and rapid alterations in the means of specific forms of suicide and among particular victim subgroups identified from local datasets. Such trends were not identifiable in national reports of death.Thesis (Ph.D.) (Research by Publication) -- University of Adelaide, School of Medicine, 2015