Predictive validity of the HCR-20 for inpatient self-harm.

Background: Few instruments have been developed to assess the risk of self-harm by psychiatric patients and the evidence for their predictive validity is limited. Given that individuals who self-harm may also engage in other-directed aggression, and that the behaviour can be a precursor to violence, we tested whether, and for which groups, the commonly used violence risk assessment HCR-20 demonstrated predictive validity for self-harm.

Procedures: A pseudo-prospective cohort study (N=504) was conducted in a UK secure/forensic mental health setting using routinely collected data. HCR-20 assessments were completed by the clinical team and incidents of self-harm during the 3months following assessment were coded from patient records.

Findings: The HCR-20 total score, H10 and R5 subscales, and SJ for violence significantly predicted self-harm; however, AUC values did not demonstrate large effect sizes (range .345 to .749). Personality disorder and impulsivity were the strongest predictors of self-harm, but the R5 scale contained the greatest proportion of relevant items. Predictive efficacy was superior for women compared with men and for those with schizophrenia or personality disorder compared with organic and developmental disorders.

Conclusions: The HCR-20 appears to be a significant predictor of self-harm. It may be possible to supplement HCR-20 ratings with case specific knowledge and additional known risk factors for self-harm to make a valuable summary judgement about the behaviour and thus minimise the need for multiple assessment tools.