Institutionen för klinisk neurovetenskap / Department of Clinical Neuroscience
Abstract
Background: The assessment of risk of violence among mentally disordered
offenders has been a controversial but well-researched area in forensic
psychology and psychiatry during the last decades. The main focus of this
research has been on the predictive validity of various risk factors and
methods of combining risk factors to gain the highest possible predictive
accuracy. In the present thesis, risk assessment is defined more broadly
than predictive accuracy, and also includes process factors,
risk-management, and the communication and decision-making associated
with risk of violence. The overall aim of this thesis was to explore the
process of structured risk assessment in its naturalistic clinical
setting.
Method: Four different samples were across 5 studies. A guideline for
structured clinical risk assessment, Historical-Clinical-Risk assessment
(HCR-20), was used in the first 4 studies. The first study used a 6
raters x 6 patients design to establish inter-rater reliability and
validity of the HCR-20. 54 forensic patients were followed over time and
monitored for inpatient violence and violence after discharge during
three risk-management conditions in study 2. A sample of 40 nurses,
assessing the same 8 patients, was included in studies 3 and 4. Finally
study 5 included a sample of 88 decisionmakers, divided into 3 groups;
Clinicians, Criminal law professionals and Controls.
Results: The HCR-20 was found to have reasonable reliability and validity
in study 1. The main finding in study 2 was that the predictive accuracy
of the HCR-20 was influenced by the intensity of risk management (AUC .64
compared to .82). In study 3 it was found that structured clinical risk
assessment was not "immune" to emotional bias in the assessment process.
43% of the variance in risk-scores could be attributed to the assessors'
emotions towards the patient. The information utilised to make the
assessment, and how the assessor values it, also influenced the
assessments in study 4. Placing value on personal interaction was more
associated with inpatient violence than with recidivism. In study 5 we
found that the inclination of making release decisions was greatly
influenced (eta2=.58 ) by the prospect of making false negative error of
judgement.
Conclusions: Structured clinical risk assessments can be undertaken in a
reliable and valid way in forensic clinical settings. Attention needs to
be paid to factors that might influence the outcome of the assessments
and the risk-management decisions that are the consequence of risk
assessment. These factors can be emotional biases, evaluation of
different kinds of information that form the basis for the process. There
needs to be an awareness of other factors than probabilities that
influence decisions about risk. It is suggested that future descriptive,
as opposed to prescriptive, research is needed on the processes and
influences on risk assessments, as they are actually conducted by
clinicians in actual forensic, psychiatric and correctional settings, and
not by researchers or trained research assistants