title: Use of risk assessment instruments to predict violence and antisocial behaviour in 73 samples involving 24 827 people: systematic review and meta-analysis.
abstract: OBJECTIVE
  To investigate the predictive validity of tools commonly used to assess the risk of violence, sexual, and criminal behaviour.
  
  
  METHODS
  Systematic review and tabular meta-analysis of replication studies following PRISMA guidelines.
  
  
  METHODS
  PsycINFO, Embase, Medline, and United States Criminal Justice Reference Service Abstracts.
  
  
  METHODS
  We included replication studies from 1 January 1995 to 1 January 2011 if they provided contingency data for the offending outcome that the tools were designed to predict. We calculated the diagnostic odds ratio, sensitivity, specificity, area under the curve, positive predictive value, negative predictive value, the number needed to detain to prevent one offence, as well as a novel performance indicator-the number safely discharged. We investigated potential sources of heterogeneity using metaregression and subgroup analyses.
  
  
  RESULTS
  Risk assessments were conducted on 73 samples comprising 24,847 participants from 13 countries, of whom 5879 (23.7%) offended over an average of 49.6 months. When used to predict violent offending, risk assessment tools produced low to moderate positive predictive values (median 41%, interquartile range 27-60%) and higher negative predictive values (91%, 81-95%), and a corresponding median number needed to detain of 2 (2-4) and number safely discharged of 10 (4-18). Instruments designed to predict violent offending performed better than those aimed at predicting sexual or general crime.
  
  
  CONCLUSIONS
  Although risk assessment tools are widely used in clinical and criminal justice settings, their predictive accuracy varies depending on how they are used. They seem to identify low risk individuals with high levels of accuracy, but their use as sole determinants of detention, sentencing, and release is not supported by the current evidence. Further research is needed to examine their contribution to treatment and management.
authors: Department of Psychiatry, University of Oxford, Warneford Hospital, Oxford OX3 7JX, UK. seena.fazel@psych.ox.ac.uk
authors: Seena
authors: S
authors: Fazel
authors: Jay P
authors: JP
authors: Singh
authors: Helen
authors: H
authors: Doll
authors: Martin
authors: M
authors: Grann
mesh_terms: D000987:Antisocial Personality Disorder / Q000453:epidemiology*; D003415:Crime / Q000523:psychology / Q000706:statistics & numerical data*; D003627:Data Interpretation, Statistical; D006801:Humans; D001523:Mental Disorders / Q000523:psychology; D011581:Psychological Tests / Q000592:standards / Q000706:statistics & numerical data*; D018570:Risk Assessment / Q000379:methods* / Q000592:standards; D012680:Sensitivity and Specificity; D012742:Sex Offenses / Q000523:psychology / Q000706:statistics & numerical data*; D014754:Violence / Q000523:psychology / Q000706:statistics & numerical data*