Treatment effects on forensic psychiatric patients measured with the HCR-20 violence risk assessment scheme

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This study focuses on the foundational issue of change in violence risk factors in forensic psychiatric patients across multiple assessment periods using the HCR-20 scheme. HCR-20 assessments performed on 150 forensic psychiatric patients at two special (forensic) hospitals in Sweden were studied in relation to the patients' time at institution, with the aim to investigate a possible relation between level of risk and time at institution. A sub-group was followed across an 18-month period of institutionalization to investigate possible changes in risk factors over time. The latter patients were assessed with the HCR-20 three times, with six months between the assessments. Patients with longer treatment times had lower scores on the HCR-20 Clinical and Risk Management sub-scales, compared to patients who had been admitted to the hospitals for a shorter period of time. This finding was particularly evident on the cross-sectional analyses with respect to the R scale. The clinical risk factors in the C scale also dropped overall in connection with treatment time across both cross-sectional and prospective analyses, although not as substantially as the R scale. The results are consistent with and provide support for the HCR-20 system's proposition that the C and R scales are dynamic, or prone to change.