["Criminal Behaviour and Mental Health, Volume 31, Issue 5, Page 321-330, October 2021. ", "\nAbstract\n\nBackground\nTreatment completion difficulties are common in forensic mental health settings and may have a profound impact on recidivism rates.\n\n\nAims\nTo test for associations between measures of risk and of security needs on the one hand and treatment non‐completion on the other among male offender‐patients in one medium security hospital.\n\n\nMethods\nWe conducted a retrospective file study in a Flemish medium security hospital. A random sample of 25 treatment non‐completers was compared to a random same‐size sample of completers, each rated, blind to outcome, on the DUNDRUM‐1 security needs scale from data recorded at the time of admission to the unit. ‘Non‐completion’ was defined as any failure to complete treatment, whether staff‐terminated or self‐terminated; in Flanders, failure to comply with the judicial conditions of placement can result in re‐imprisonment. We used binary logistic regression to test relationships between treatment completion/non‐completion and security need, measured with the DUNDRUM‐1, together with a range of possible confounding variables.\n\n\nResults\nMost patients had psychosis and/or personality disorder and often substance use disorders also. Treatment non‐completion was invariably staff ordered because of security breaches. DUNDRUM‐1 and PCL‐R Facet 4 scores at the time of admission and HCR‐20 scores during admission were significantly higher among non‐completers than completers, but after binary logistic regression, only the DUNDRUM‐1 rating was independently associated with non‐completion.\n\n\nConclusions\nOur study showed that an admission DUNDRUM‐1 rating, indicating levels of security need, co‐varies only to a small extent with the historical items of the HCR‐20, so may be regarded as measuring complementary domains. While conditions in Flanders at the time of the study complicated it in that medium security hospital units offered the highest level of hospital security available, the finding that non‐completion of treatment was particularly likely when the DUNDRUM‐1 indicated a higher security need than facilities could provide may have implications for all secure hospital services.\n\n"]