MHDCD Project

2.2 The MHDCD Study

2.2.1 Context for the MHDCD Study

The study presented in this report builds on an ARC Linkage project, People with mental health disorders and cognitive disability (MHDCD) in the criminal justice system in NSW[1] conducted 2006-09. The MHDCD Project created a merged Dataset containing lifelong administrative information on a cohort of 2,731 persons who have been in prison in NSW and whose MHDCD diagnoses are known. The cohort is a purposive sample drawn from the NSW Inmate Health Survey 2001 and the Statewide Disability Database of Corrective Services NSW, with data on the 2,731 individuals provided by criminal justice and human service agencies. Project partnerships and/or collaborations were established with all NSW criminal justice agencies (Corrective Services, Police, Juvenile Justice, Courts, Legal Aid) and human service agencies (Housing, Ageing Disability and Home Care, Community Services, Justice Health and NSW Health through the Centre for Health Record Linkage giving access to Mortality, Pharmacotherapy and Admitted Patient databases).

The MHDCD project team developed an innovative method of collecting, merging and analysing data relating to complex individuals and populations. Each individual in the cohort was matched in each agency and all matches for each person for that agency were added to the database as an agency-specific subset. This allows merging of data related to each individual from any subset with any other subset, with the potential to create specifically compiled subsets of interest, overall administrative de-identified life course ‘pathway’ case studies for individuals in the Dataset, aggregated subset pathways and patterns of effects of agency interactions with individuals, subgroups and other agencies. Merging data across the criminal justice sub-systems and with relevant human services provides a broad, dynamic, trans-criminal justice and human service understanding of the involvement of vulnerable people in the criminal justice system. It sidesteps the problem of prospective approaches, which potentially require up to 30 years or more and risk yielding very limited numbers of persons in the groups of interest. The data gathered in the MHDCD Dataset is of extraordinary richness and depth. For example, it includes information on all police incidents in which an individual was a person of interest or victim; all charges and their outcomes; all court appearances; all episodes of juvenile and adult custody; all housing applications and their outcomes; and all hospital admissions and associated diagnoses, thus allowing for detailed and powerful analysis.


[1] ARC Linkage Project at UNSW ‘People with mental health disorders and cognitive disability in the criminal justice system in NSW’ Chief Investigators: Eileen Baldry, Leanne Dowse, Ian Webster; Partner Investigators: Tony Butler, Simon Eyland and Jim Simpson.

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