title: Self-harm in prisons in England and Wales: an epidemiological study of prevalence, risk factors, clustering, and subsequent suicide.
abstract: BACKGROUND
  Self-harm and suicide are common in prisoners, yet robust information on the full extent and characteristics of people at risk of self-harm is scant. Furthermore, understanding how frequently self-harm is followed by suicide, and in which prisoners this progression is most likely to happen, is important. We did a case-control study of all prisoners in England and Wales to ascertain the prevalence of self-harm in this population, associated risk factors, clustering effects, and risk of subsequent suicide after self-harm.
  
  
  METHODS
  Records of self-harm incidents in all prisons in England and Wales were gathered routinely between January, 2004, and December, 2009. We did a case-control comparison of prisoners who self-harmed and those who did not between January, 2006, and December, 2009. We also used a Bayesian approach to look at clustering of people who self-harmed. Prisoners who self-harmed and subsequently died by suicide in prison were compared with other inmates who self-harmed.
  
  
  RESULTS
  139,195 self-harm incidents were recorded in 26,510 individual prisoners between 2004 and 2009; 5-6% of male prisoners and 20-24% of female inmates self-harmed every year. Self-harm rates were more than ten times higher in female prisoners than in male inmates. Repetition of self-harm was common, particularly in women and teenage girls, in whom a subgroup of 102 prisoners accounted for 17,307 episodes. In both sexes, self-harm was associated with younger age, white ethnic origin, prison type, and a life sentence or being unsentenced; in female inmates, committing a violent offence against an individual was also a factor. Substantial evidence was noted of clustering in time and location of prisoners who self-harmed (adjusted intra-class correlation 0·15, 95% CI 0·11-0·18). 109 subsequent suicides in prison were reported in individuals who self-harmed; the risk was higher in those who self-harmed than in the general prison population, and more than half the deaths occurred within a month of self-harm. Risk factors for suicide after self-harm in male prisoners were older age and a previous self-harm incident of high or moderate lethality; in female inmates, a history of more than five self-harm incidents within a year was associated with subsequent suicide.
  
  
  CONCLUSIONS
  The burden of self-harm in prisoners is substantial, particularly in women. Self-harm in prison is associated with subsequent suicide in this setting. Prevention and treatment of self-harm in prisoners is an essential component of suicide prevention in prisons.
  
  
  BACKGROUND
  Wellcome Trust, National Institute for Health Research, National Offender Management Service, and Department of Health.
authors.affiliation: Centre for Suicide Research, Department of Psychiatry, University of Oxford, Oxford, UK.
authors.forename: Keith
authors.initials: K
authors.lastname: Hawton
authors.affiliation: Clinical Trials Unit, National Perinatal Epidemiology Unit, University of Oxford, Oxford, UK.
authors.forename: Louise
authors.initials: L
authors.lastname: Linsell
authors.affiliation: Equality, Rights and Decency Group, National Offender Management Service, Ministry of Justice, London, UK.
authors.forename: Tunde
authors.initials: T
authors.lastname: Adeniji
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institute, Stockholm, Sweden.
authors.forename: Amir
authors.initials: A
authors.lastname: Sariaslan
authors.affiliation: Department of Psychiatry, University of Oxford, Oxford, UK. Electronic address: seena.fazel@psych.ox.ac.uk.
authors.forename: Seena
authors.initials: S
authors.lastname: Fazel
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001499:Bayes Theorem; D016022:Case-Control Studies; D004739:England / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011329:Prisoners / Q000523:psychology* / Q000706:statistics & numerical data; D011330:Prisons / Q000706:statistics & numerical data*; D012307:Risk Factors; D016728:Self-Injurious Behavior / Q000453:epidemiology*; D013405:Suicide / Q000706:statistics & numerical data*; D014852:Wales / Q000453:epidemiology; D055815:Young Adult