A national case-control study of risk factors among prisoners in England and Wales

To examine risk factors for suicide among prisoners in a national population. The Ministry of Justice identified all suicides occurring in prisons in England and Wales between 2005 and 2008. Two hundred and twenty suicides were matched to 220 living controls on age, gender, date of reception into prison and establishment type. Relative risks for clinical, custodial, service-response and socio-demographic characteristics were estimated using conditional logistic regression models. Having a history of violence and several indicators of past or current psychiatric illness were strong predictors at univariate level. Prisoners who died by suicide were over nine times more likely than controls to have been identified and managed as being at-risk of self-harm/suicide during the prison term. Multivariate analysis identified five mutually independent predictors: previous psychiatric service contact, history of self-harm, single cell occupation, remand status, and non-white ethnicity. Suicide risk is elevated among certain types of prisoners, and targeted suicide prevention strategies should be developed for the monitoring, care and support of the high-risk groups that we identified. Further research is needed to determine the causal mechanisms that explain why some prisoners have a higher suicide risk than their peers.