Suicides by persons reported as missing prior to death: a retrospective cohort study
- Australian Institute for Suicide Research and Prevention, World Health Organization Collaborating Centre for Research and Training in Suicide Prevention, National Centre of Excellence in Suicide Prevention, Griffith University, Mt Gravatt, Australia
- Correspondence to Professor Diego De Leo;
- Received 11 November 2011
- Accepted 16 February 2012
- Published 26 March 2012
Objective A first study to compare suicides by missing persons with other suicide cases.
Design Retrospective cohort study for the period 1994–2007.
Geographical location Queensland, Australia.
Population 194 suicides by missing persons and 7545 other suicides were identified through the Queensland Suicide Register and the National Coroners Information System.
Main outcome measure χ2 statistics and binary logistic regression were used to identify distinct characteristics of suicides by missing persons.
Results Compared with other suicide cases, missing persons significantly more often died by motor vehicle exhaust gas toxicity (23.7% vs 16.4%; χ2=7.32, p<0.01), jumping from height (6.7% vs 3.2%; χ2=7.08, p<0.01) or drowning (8.2% vs 1.8%; χ2=39.53, p<0.01), but less frequently by hanging (29.4% vs 39.9%; χ2=8.82, p<0.01). They were most frequently located in natural outdoors locations (58.2% vs 11.1%; χ2=388.25, p<0.01). Persons gone missing were less likely to have lived alone at time of death (OR 0.45, 95% CI 0.26 to 0.76), yet more likely to be institutionalised (OR 3.12, 95% CI 1.28 to 7.64). They were less likely to have been physically ill (OR 0.64, 95% CI 0.43 to 0.95) or have a history of problematic consumptions of alcohol (OR 0.52, 95% CI 0.31 to 0.87). In comparison to other suicide cases, missing persons more often communicated their suicidal intent prior to death (OR 1.58, 95% CI 1.13 to 2.22).
Conclusions Suicides by missing persons show several distinct characteristics in comparisons to other suicides. The findings have implications for development of suicide prevention strategies focusing on early identification and interventions targeting this group. In particular, it may offer assistance to police in designing risk assessment procedures and subsequent investigations of missing persons.
To cite: Sveticic J, Too LS, De Leo D. Suicides by persons reported as missing prior to death: a retrospective cohort study. BMJ Open 2012;2:e000607. doi:10.1136/bmjopen-2011-000607
Contributors JS participated in the design of the study, performed the statistical analysis and contributed to the writing of the paper. LST contributed to the data analysis and the writing of the paper. DDL conceived the project, participated in the design of the study and helped to finalise the manuscript for publication. All authors read and approved the final manuscript.
Funding Queensland Health provides continuous funding and support in the management of Queensland Suicide Register, which was used as the primary data source for the study.
Competing interest None.
Ethics approval The use of data from the Queensland Suicide Register has continuing ethnical approval from the Griffith University Ethics Committee (GU Ref No: CSR/02/10/HREC), and use of data from National Coronial Information System has approval by Department of Justice Human Research Ethics (CF/09/5759).
Provenance and peer review Not commissioned; externally peer reviewed.
Data sharing statement No additional data from our study are available for sharing.
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