Abstract
SummaryBackgroundSelf-harm is a leading cause of morbidity in prisoners. Although a wide range of risk factors for self-harm in prisoners has been identified, the strength and consistency of effect sizes is uncertain. We aimed to synthesise evidence and assess the risk factors associated with self-harm inside prison.MethodsIn this systematic review and meta-analysis, we searched four electronic databases (PubMed, Embase, Web of Science, and PsycINFO) for observational studies on risk factors for self-harm in prisoners published from database inception to Oct 31, 2019, supplemented through correspondence with authors of studies. We included primary studies involving adults sampled from general prison populations who self-harmed in prison and a comparison group without self-harm in prison. We excluded studies with qualitative or ecological designs, those that reported on lifetime measures of self-harm or on selected samples of prisoners, and those with a comparison group that was not appropriate or not based on general prison populations. Data were extracted from the articles and requested from study authors. Our primary outcome was the risk of self-harm for risk factors in prisoners. We pooled effect sizes as odds ratios (OR) using random effects models for each risk factor examined in at least three distinct samples. We assessed study quality on the basis of the Newcastle-Ottawa Scale and examined between-study heterogeneity. The study protocol was registered with PROSPERO, CRD42018087915.FindingsWe identified 35 independent studies from 20 countries comprising a total of 663 735 prisoners, of whom 24 978 (3·8%) had self-harmed in prison. Across the 40 risk factors examined, the strongest associations with self-harm in prison were found for suicide-related antecedents, including current or recent suicidal ideation (OR 13·8, 95% CI 8·6–22·1; I2=49%), lifetime history of suicidal ideation (8·9, 6·1–13·0; I2=56%), and previous self-harm (6·6, 5·3–8·3; I2=55%). Any current psychiatric diagnosis was also strongly associated with self-harm (8·1, 7·0–9·4; I2=0%), particularly major depression (9·3, 2·9–29·5; I2=91%) and borderline personality disorder (9·2, 3·7–22·5; I2=81%). Prison-specific environmental risk factors for self-harm included solitary confinement (5·6, 2·7–11·6; I2=98%), disciplinary infractions (3·5, 1·2–9·7; I2=99%), and experiencing sexual or physical victimisation while in prison (3·2, 2·1–4·8; I2=44%). Sociodemographic (OR range 1·5–2·5) and criminological (1·8–2·3) factors were only modestly associated with self-harm in prison. We did not find clear evidence of publication bias.InterpretationThe wide range of risk factors across clinical and custody-related domains underscores the need for a comprehensive, prison-wide approach towards preventing self-harm in prison. This approach should incorporate both population and targeted strategies, with multiagency collaboration between the services for mental health, social care, and criminal justice having a key role.FundingWellcome Trust.
Highlights
More than 11 million individuals are imprisoned world wide.[1]
We identified many risk factors for self-harm across sociodemographic, criminological, custodial, clinical, and historical domains, the strongest associations were found for suicide-related exposures and markers of psychiatric morbidity
Implications of all the available evidence Our results show that risk factors associated with self-harm in prisoners include a range of potentially modifiable clinical, psychosocial, and environmental factors
Summary
More than 11 million individuals are imprisoned world wide.[1]. People who pass through prisons often have poor health profiles, including high frequencies of self-harm.[2,3,4] Self-harm is a leading cause of morbidity in prisoners; the annual prevalence of self-harm in prison has been estimated to be 5–6% in men and 20–24% in women,[5] which greatly exceeds the less than 1% of adults in the general population who self-harm each year.[6,7,8] Prisoners who self-harm are at a six to eight times increased risk of suicide while incarcerated[9,10] and remain so after release into the community.[11,12] Half of people who die by suicide in prison have a recorded history of self-harm,[9,10] with many deaths occurring within a month of self-harm.[5]. Understanding the risk factors for self-harm can help to improve prevention efforts in this population at high risk, if there is evidence of modifiable risk facto
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
