A Novel Approach to Determining Violence Risk in Schizophrenia: Developing a Stepped Strategy in 13,806 Discharged Patients

Singh, J. P., Grann, M., Lichtenstein, P., Långström, N., & Fazel, S. (2012). A novel approach to determining violence risk in schizophrenia: Developing a stepped strategy in 13,806 discharged patients. PLoS ONE, 7, e31727.

9 Pages Posted: 31 Jul 2014

See all articles by Jay Singh

Jay Singh

Global Institute of Forensic Research; Høgskolen i Molde

Martin Grann

Karolinska Institutet

Paul Lichtenstein

Karolinska Institutet - Department of Medical Epidemiology and Biostatistics

Niklas Langstrom

Karolinska Institutet

Seena Fazel

University of Oxford

Date Written: 2012

Abstract

Clinical guidelines recommend that violence risk be assessed in schizophrenia. Current approaches are resource-intensive as they employ detailed clinical assessments of dangerousness for most patients. An alternative approach would be to first screen out patients at very low risk of future violence prior to more costly and time-consuming assessments. In order to implement such a stepped strategy, we developed a simple tool to screen out individuals with schizophrenia at very low risk of violent offending. We merged high quality Swedish national registers containing information on psychiatric diagnoses,socio-demographic factors, and violent crime. A cohort of 13,806 individuals with hospital discharge diagnoses of schizophrenia was identified and followed for up to 33 years for violent crime. Cox regression was used to determine risk factors for violent crime and construct the screening tool, the predictive validity of which was measured using four outcome statistics. The instrument was calibrated on 6,903 participants and cross-validated using three independent replication samples of 2,301 participants each. Regression analyses resulted in a tool composed of five items: male sex, previous criminal conviction, young age at assessment, comorbid alcohol abuse, and comorbid drug abuse. At 5 years after discharge, the instrument had a negative predictive value of 0.99 (95% CI=0.98–0.99), meaning that very few individuals who the tool screened out (n=2,359 out of original sample of 6,903) were subsequently convicted of a violent offence. Screening out patients who are at very low risk of violence prior to more detailed clinical assessment may assist the risk assessment process in schizophrenia.

Keywords: Violence risk assessment, Schizophrenia, Stepped strategy

Suggested Citation

Singh, Jay and Grann, Martin and Lichtenstein, Paul and Langstrom, Niklas and Fazel, Seena, A Novel Approach to Determining Violence Risk in Schizophrenia: Developing a Stepped Strategy in 13,806 Discharged Patients (2012). Singh, J. P., Grann, M., Lichtenstein, P., Långström, N., & Fazel, S. (2012). A novel approach to determining violence risk in schizophrenia: Developing a stepped strategy in 13,806 discharged patients. PLoS ONE, 7, e31727.. Available at SSRN: https://ssrn.com/abstract=2473260

Jay Singh

Global Institute of Forensic Research ( email )

11700 Plaza America Drive
Suite 810
Reston, VA 20190
United States

HOME PAGE: http://www.gifrinc.com

Høgskolen i Molde ( email )

Molde NO-6405
Norway

Martin Grann

Karolinska Institutet ( email )

Granits väg 4
Solna, Stockholm 17171
Sweden

Paul Lichtenstein

Karolinska Institutet - Department of Medical Epidemiology and Biostatistics ( email )

SE-171 82 Solna
Sweden

Niklas Langstrom

Karolinska Institutet ( email )

Granits väg 4
Solna, Stockholm 17171
Sweden

Seena Fazel (Contact Author)

University of Oxford ( email )

Mansfield Road
Oxford, Oxfordshire OX1 4AU
United Kingdom

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