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10.1177/0093854804270630 CRIMINAL JUSTICE AND BEHAVIOR Hilton et al. / COMMUNICATING RISK INFORMATION

ARTICLE

COMMUNICATING VIOLENCE RISK INFORMATION TO FORENSIC DECISION MAKERS N. ZOE HILTON GRANT T. HARRIS KELLY RAWSON CRAIG A. BEACH Mental Health Centre, Penetanguishene, Ontario, Canada Although actuarial risk assessments have the potential to improve forensic decision making, clinicians neither prefer nor use them. Effective communication is an important next step for study. The decisions of 60 forensic clinicians (from a range of disciplines) were examined for possible effects related to case information, a likelihood of violent recidivism statement, and actuarial risk level. When no likelihood statement was provided, participants reported using case information containing risk factors to appraise risk. A summary likelihood statement, however, improved communication of risk. Participants were more likely to defer a security decision when there was no likelihood statement. Participants made little distinction between likelihood of violence and comparative risk. These findings suggest strategies for improving violence risk communication. Keywords: risk communication; risk assessment; violence; decision making

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he last decade has seen considerable progress in the assessment of violence risk using empirically derived assessments for sex offenders and violent offenders in general (e.g., Hanson & Thornton,

AUTHOR NOTE: We would like to thank the staff who participated in this study; Shari McKee, Vern Quinsey, Marnie Rice, and Michael Seto for helpful comments on earlier drafts; and Sonja Dey for typing the manuscript. Correspondence concerning this manuscript should be addressed to N. Zoe Hilton at Research Department, MHCP, 500 Church Street, Penetanguishene, ON, L9M 1G3, Canada; E-mail: [email protected] CRIMINAL JUSTICE AND BEHAVIOR, Vol. 32 No. 1, February 2005 97-116 DOI: 10.1177/0093854804270630 © 2005 American Association for Correctional and Forensic Psychology

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2000; Harris, Rice, & Quinsey, 1993; Quinsey, Harris, Rice, & Cormier, 1998). There is ample evidence that actuarial assessments provide the most accurate predictions of violent recidivism (e.g., Grove, Zald, Lebow, Snitz, & Nelson, 2000; Monahan, 1996). Because valid risk assessment tools are available, there is optimism that risk-management decisions will improve (e.g., Kropp & Hart, 2000). Actuarial risk information is not routinely used in forensic decision making, however, even when available (Hilton & Simmons, 2001; Taylor, Goldberg, Leese, Butwell, & Reed, 1999). Researchers have identified effective communication of risk information and the flow from assessment to effective risk-related decisions as the next steps in risk assessment research (Fuller & Cowan, 1999; Heilbrun, O’Neill, Strohman, Bowman, & Philipson, 2000; Monahan, 1996). THE PREFERENCES FOR RISK INFORMATION

Few studies have examined the use of risk information. In a survey of 55 forensic psychiatrists and psychologists, the most preferred risk assessments either describe “recent and present behavior, give clinical impressions based on history, current behavior, mental status, and dynamics, and make a prediction,” or describe “how specific risk factors raise or lower risk, and present a conclusion” (Heilbrun, Philipson, Berman, & Warren, 1999, p. 403). Most participants rejected probability estimates, moreover, claiming they would be scientifically unjustified or unfeasible because of lack of useful scales. The investigators noted that research has shown these objections to be erroneous (Heilbrun et al., 1999). Nevertheless, in a subsequent study of 71 forensic psychiatrists and psychologists, percentage statements of the likelihood of future violence continued to be the least popular (Heilbrun et al., 2000). Individual dynamic risk factors together with a list of interventions for each factor were the most popular. Some risk assessment guides instruct users to apply only such categories as low, moderate, or high (e.g., Webster, Douglas, Eaves, & Hart, 1997). Categorical statements were also highly favored by clinicians in the Heilbrun et al. (2000) study. Implicit in these statements is comparative risk—that is, an individual’s rank relative to a referent population. Slovic and Monahan (1995) reported that forensic clinicians (primarily psychologists but also psychiatrists and social work-

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ers) used probability as though it were comparative, expressing the likelihood of violence in two cases relative to each other. This finding is consistent with a substantial amount of literature showing that survey responses vary as a function of the response options (Schwarz, 1999). Whether, and under what circumstances, clinicians can distinguish between comparative risk and the actual likelihood of violence remains unclear. The preference for statements implying comparative categories, together with the development of risk assessments yielding probability estimates, also leads to the question of whether forensic clinicians can accurately estimate comparative risk if they know the individual likelihood. THE EFFECTS OF RISK INFORMATION

Preference for comparative categorical risk statements might be the result of a general discomfort with statistical information. Opponents of actuarial tools assert population data cannot be applied to individuals (e.g., Litwack, 2001; Price, 1997). This implies some clinicians could not use information related to violence risk if probability estimates were provided. The current authors believe forensic clinicians are more familiar with aggregate information when making individual inferences than such criticisms suggest. Studies of statistical comprehension indicate, however, that well-educated adults process frequencies more easily than probabilities (Brace, Cosmides, & Tooby, 1998; Manktelow, 1999; Sykes & Johnson, 1999). Slovic, Monahan, and MacGregor (2000) surveyed members of the American Academy of Psychiatry and Law and reported these professionals rated the likelihood of violence higher and recommended more security precautions when using frequency rather than probability. The authors suggested that probability (e.g., 20%) is less evocative of danger than the equivalent frequency (e.g., 2 out of 10). Support for this idea came from a survey of American Psychological Association members with an interest in clinical and forensic psychology (Monahan et al., 2002). Explicit descriptions of violent acts together with frequency statements resulted in fewer recommendations for the discharge of psychiatric patients. This effect was confined to the 102 clinicians working in forensic settings, and the authors speculated such clinicians were sensitized to frightening

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information. Depending on how information was presented, 46.4% to 80.0% of clinicians refused discharge for hypothetical patients with a 20% likelihood of recidivism. In a just forensic system, such variation in decision making could not be supported. THE EFFECTIVENESS OF COMMUNICATION

The research on risk-related decision making cannot be used to evaluate the quality of decisions because of the absence of unambiguous performance standards. Specifically, without an objective index of risk, conclusions about whether frequency or probability information (or indeed risk-irrelevant details of an offense) lead to more accurate or proficient decision making are impossible. The next research step is evaluating decision-making performance, and to do that, a performance standard is required. We argue that good forensic decisions place higher risk cases under greater supervision than lower risk cases. It is acknowledged the cut-offs at which offenders are sufficiently high risk to be detained, or sufficiently low risk to be released, partly depend on nonempirical considerations (e.g., number of secure beds available, judgments about balancing public safety and offenders’ liberty). All else equal, however, placing objectively higher risk offenders under greater security and supervision than lower risk offenders results in greater public safety than failing to distinguish on the basis of risk. The greater the distinction (in security and related services) between high- and low-risk cases, the better the decision and, by inference, the more effective the associated communication. The present study was a preliminary attempt to discover what information about risk leads to greater distinctions in decisions between objectively high- and low-risk cases. As an objective index of risk, the Violence Risk Appraisal Guide (VRAG; Harris et al., 1993; Quinsey et al., 1998) was used. The VRAG was constructed and cross-validated on violent offenders undergoing psychiatric evaluation, about half of whom were subsequently convicted and most of the remainder detained in a secure psychiatric facility. Its predictive accuracy for community and institutional violence has been demonstrated in several correctional and psychiatric samples (e.g., Bèlanger & Earls, 1996; Grann, Belfrage, & Tengström, 2000; Hanson & Harris, 2000; Harris, Rice, & Cormier,


2002; Harris et al., 2003; Polvi, 2001; Quinsey, Coleman, Jones, & Altrows, 1997; Rice & Harris, 1997). Standard VRAG reports (Quinsey et al., 1998) include the operational definition of violent recidivism and the assessee’s risk-relevant history, percentile rank, category of risk (out of nine categories), and probability (expressed as a percentage) of violent recidivism within 10 years of opportunity. Subsequent research has replicated the probabilities in new samples (Harris et al., 2002, 2003). The present study used a summary of either risk-relevant or riskirrelevant case information followed by the likelihood of recidivism stated as either a percentage (e.g., 64%), a frequency (e.g., 64 out of 100 offenders), or followed by a statement that insufficient information was available for an assessment. The information presented to participants was limited because Mamuza (2001) elicited more accurate estimates of risk when information was made salient. Also, Heilbrun et al. (1999; Heilbrun et al., 2000) and Slovic (Slovic & Monahan, 1995; Slovic et al., 2000) obtained clear effects with only a brief paragraph and single statement of risk, whereas Quinsey and Ambtman (1979) found that participants did not use case information when it was very extensive. In this study of hypothetical decisions by experienced forensic clinicians, violence risk was manipulated within subjects, and case history information (risk-relevant vs. risk-irrelevant) and riskassessment statement (percentage vs. frequency vs. not available) were varied between subjects. The following questions were asked: To what extent are forensic clinicians’ perceptions of risk and decisions sensitive to statements about likelihood of violence and to riskrelevant case information? Does sensitivity vary with the availability of actuarial likelihood statements? We predicted: (1) estimated likelihood of violent recidivism would be more accurate (i.e., closer to the objective estimate) with risk-relevant rather than with risk-irrelevant case information, with a summary risk statement than without, and with a frequency-based risk statement than a percentage-based risk statement; (2) estimated likelihood of violence would be positively associated with estimates of comparative risk; (3) decisions would be positively associated with risk estimate (i.e., the greater the estimated risk, the more security recommended); and (4) frequency-based risk statements would yield more proficient decisions than percentage-

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based statements (i.e., greater distinction between relatively high- and low-risk cases). METHOD PARTICIPANTS AND PROCEDURE

The study was conducted in a 160-bed forensic psychiatric hospital. Of approximately 200 ward-based clinical staff, 60 participated, representing all clinical disciplines (i.e., nursing, psychiatry, psychology, social work, recreation, and occupational therapy). Clinicians routinely participate in annual case conferences and offer security recommendations to the review board, whose decisions are highly correlated with case conference recommendations (r = .78; Hilton & Simmons, 2001). To ensure anonymity, discipline and other identifiers were not recorded. Potential participants were approached while attending routine case conferences. Questionnaires from different conditions were distributed at random, and participant recruitment continued until all cells were filled (n = 10 per cell). Eleven volunteers were unable to attend scheduled conferences and participated during specially arranged meetings. No one declined to attend these meetings, but two clinicians declined to participate at case conferences, a 3.2% refusal rate. Questionnaires were administered with written and oral instructions, including that participation was anonymous and voluntary. Participants were told that case summaries were short and that they could indicate there was not enough information. MATERIALS

Two case histories consisting of relatively high- and low-risk individuals were presented in counterbalanced order. Each participant read both a higher risk and a lower risk case in one case-history-bysummary-risk-information condition. Risk level. The lower risk case history corresponded to a 10-year probability of violent recidivism of .24 and the higher risk case to a probability of .64. These rates were approximately equidistant from


the known base rate of violent recidivism for the institution, that is, 43% over 10 years (Rice & Harris, 1995). The cases also corresponded to percentile ranks (an index of comparative risk) of 23 and 88, respectively. No statement of comparative risk, however, was provided to participants. Case history. Each case history was a paragraph about a male patient in maximum security. In the risk-relevant case history, the paragraph described the offender’s status on the 12 VRAG items (although the VRAG itself was not mentioned). The risk-irrelevant case history contained 12 items that have been empirically studied and found unrelated to violent recidivism (e.g., Bonta, Law, & Hanson, 1998). Referring to the empirical literature, we excluded information clinicians might erroneously think relevant to risk (e.g., Hilton & Simmons, 2001; Quinsey et al., 1998). Sample cases are in Appendix A, and each was prefaced with a statement that the index offense was attempted murder. Summary likelihood statement. Each case history concluded with one of three versions of a summary likelihood statement. The likelihood of reoffending expressed either (a) as a percentage (e.g., “Among mentally disordered offenders, approximately 64% in Hugh’s risk category reoffended violently within an average of 10 years after release”), (b) as a frequency (e.g., “When 100 mentally disordered offenders in Dave’s category were released to the community, 24 of them committed another violent offense within an average of 10 years”), or (c) no summary statement, but instead that “there was not enough information on Larry’s file to score a risk assessment.” Note that objective risk level was not actually manipulated in conditions with risk-irrelevant case histories and no summary likelihood statement (i.e., there was no valid way to infer anything about risk). Questionnaire items. After reading each case history, participants estimated on “a scale from 1 to 100” the patient’s likelihood of reoffending violently within 10 years. They estimated comparative risk by marking an “x” on a 100 millimeter line to show how his risk compared with other forensic patients. They also indicated a recommended security decision on a checklist that included the options nor-

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mally available at real case conferences: stay in maximum security; stay but review again in less than a year; transfer to medium security without community access; transfer to medium security with community access; transfer to minimum security; release to the community. Participants also indicated, in their own words, the information that most affected their recommendation. This permitted some open expression and served as a check on awareness of the information provided in the experimental conditions. This question was not designed to test what actually influenced decisions (this test was achieved by the controlled variables) nor to test why or when clinicians stray from the actuarial or case information. Questionnaire items are shown in Appendix B. RESULTS ESTIMATED LIKELIHOOD AND COMPARATIVE RISK

Figure 1 shows the mean risk estimates for each condition. The overall likelihood of recidivism estimated mean was 61.18 (SD = 22.55) for the higher risk case and 31.21 (SD = 17.90) for the lower risk case. Scenarios with risk-irrelevant case histories and no summary likelihood statement were excluded from these two means. In all other conditions, the actuarial risk was either given or could be inferred from information in the scenario (or both) so that it was reasonable to compute an accuracy score reflecting how close estimates were to the actuarially determined objective risk. An accuracy score was computed by subtracting each participant’s estimate of the likelihood of recidivism from the objective, actuarial risk (64 or 24). For example, if a participant estimated the higher risk (64%) case as having a 75% risk of reoffending, the accuracy score was 64 – 75 = –11. For ease of interpretation, the absolute difference was multiplied by –1 so that complete agreement between the estimate and the actuarial risk (i.e., perfect accuracy) was indicated by an accuracy score of zero, and greater error was indicated by more negative scores. A 2 (Case Information) × 3 (Risk Statement) × 2 (Risk Level) ANOVA revealed a main effect of summary statement, F(2, 83) =


Figure 1:

Mean Estimates of (a) Likelihood of Recidivism and (b) Comparative Risk as a Function of Risk Level, Case Information, and Summary Likelihood Statement

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4.36, p < .05, and an interaction of summary statement and case information, F(2, 83) = 3.63, p < .05. Contrary to Hypothesis 1, frequency statements (M = –11.64, SD = 17.13) did not yield greater accuracy than percentage statements (M = –12.97, SD = 15.74), t(68) = 0.34, ns, 95% CI of difference = –9.19, 6.53 (degrees of freedom vary because some participants omitted items stating they had insufficient information to answer). Either summary statement yielded better accuracy, however, than no summary statement, (M = –23.00, SD = 17.09), 95% CI = –15.95, –30.05, in partial support of Hypothesis 1. Examination of the risk estimates (Figure 1) indicated that adding risk-relevant case history to percentage or frequency summary likelihood statements tended to increase the estimated likelihood above the actuarial risk, thereby rendering this condition less accurate (M = –19.88, SD = 15.10, 95% CI = –12.12, –27.65; and M = –14.05, SD = 18.71, 95% CI = –5.29, –22.81, respectively) than the corresponding risk-irrelevant case history condition (M = –6.06, SD = 13.46, 95% CI = 0, –12.98; and M = –8.63, SD = 14.97, 95% CI = .65, 16.60). More risk information appeared to result in perceptions of more risk rather than in more accurate estimates. As predicted by Hypothesis 2, estimates of comparative risk were highly associated with estimates of likelihood, r(91) = .89, p < .001. A 2 × 3 × 2 ANOVA revealed only a main effect of risk level, F(1, 89) = 19.54, p < .001. An accuracy score for comparative risk estimates was calculated in a similar manner to that for the likelihood estimates. Comparative risk accuracy scores for the two risk levels revealed greater accuracy for lower risk cases (M = –12.07, SD = 10.47) than higher risk cases (M = –29.62, SD = 23.46), t(49) = 4.78, p < .001, 95% CI of difference = –25.47, –9.60. Examination of the comparative risk estimates (Figure 1) indicated that participants estimated comparative risk as essentially equivalent to the likelihood. Because the percentile rank and likelihood of violent recidivism were coincidentally nearly equal for the lower risk cases, estimates of comparative risk resulted in the appearance of better estimation in these conditions. SECURITY DECISIONS

Most cases (98, 81.6%) yielded a recommended security placement, with most of these (59, 60.2%) conservative (i.e., remain in


Likelihood Statement

%

Freq

No

4

2

0

-2

-4 Risk Relevant

Risk Irrelevant

Case Information

Figure 2:

Mean Difference (and 95% Confidence Intervals) Between Higher and Lower Risk Cases in Security Decision Note. Decision scaled from (1) release to the community to (6) maximum security without early review.

maximum security). These decisions were converted to an ordinal scale ranging from (1) release to the community to (6) maximum security without early review. Consistent with Hypothesis 3, estimated likelihood of violent recidivism and comparative risk were significantly related to this security decision scale, rs = .60 and .54, ps < .001, respectively. Thus, about a third of the variance in security decisions could be attributed to estimates of the absolute and comparative likelihood of subsequent violence. As an index of decision-making performance, the difference between the security decisions for higher and lower risk cases was computed for each participant so that a positive score indicated the higher risk case was recommended for greater security (Figure 2). Overall, this difference score was not significantly

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different from zero, (M = –0.22, SD = 2.04) and was related to the general discrimination exhibited in estimated likelihood of recidivism r(39) = .36, p < .05. Participants who made larger distinctions in their risk estimates made larger distinctions in security decisions. Contrary to Hypothesis 4, percentage summary statements (M = 1.06, SD = 1.30) yielded larger differences in security decisions than did frequency statements (M = –0.29, SD = 2.25) and did so in the direction of better decision-making performance, t(31) = 2.10, p < .05, 95% CI of difference = .004, 2.67. Figure 2 reveals a tendency for higher risk cases to be detained in maximum security less when there was a frequency statement. Percentage statements rather than frequency or no summary likelihood statements were associated with security discrimination, r(46) = .31, p < .05. Controlling for relevance of case information did not reduce this association. ABSENT SUMMARY LIKELIHOOD STATEMENTS

Without a summary likelihood statement or a risk-relevant case history, the mean estimated likelihood of violent recidivism was relatively high at 57.2 (SD = 21.1) compared with the normative base rate of 43%. Quite reasonably, however, estimated comparative risk was 50.2 (SD = 17.0). Also, when there was no summary statement, participants were more likely to respond that there was not enough information to make a security decision (14, 35.0%) than when the summary statement was either percentage-based (3, 7.5%) or frequency-based (5, 12.5%), χ2(2, N = 120) = 11.47, p < .01. Adding a risk-relevant case history did not alter this reluctance to make a forensic decision without a summary likelihood statement. Having no information or having both a summary likelihood statement and a risk-relevant case history led to greater conservatism (11, 55.0% and 24, 60.0% recommended to maximum security, respectively) than having only a summary statement (14, 35.0%) or a relevant case history (8, 40.0%). Among cases in which recommendations were made, having no useful information (irrelevant information and no summary statement) led to a conservatism matched only by higher risk, percentage-based, risk-relevant cases.

Hilton et al. / COMMUNICATING RISK INFORMATION 109 INFORMATION NOMINATED AS AFFECTING DECISIONS

In most (94, 78.3%) cases, participants gave at least one response to the question about what information most affected their security decisions. All 274 responses were coded by the fourth author, using seven categories derived from a simple content analysis of the themes in participants’responses. Although this analysis was somewhat subjective, a random 28 (10.2%) cases coded by an independent rater showed acceptable reliability (kappa = .74, p < .01). Most responses identified information given in the case history and varied somewhat unsurprisingly as a function of the case history condition. Statistically significant differences were obtained for patient history, nominated more often in the risk-relevant condition, 93% versus 7%, significantly different from 50/50 in a binomial test, p < .05; and condition in hospital, nominated more often in the risk-irrelevant condition, 90% versus 10%, p < .05, binomial test. There was no effect of risk level. Some participants (31.0%) nominated information they wanted, yielding 255 responses including in-hospital functioning (78, 30.5%), diagnosis (33, 12.9%), patient history (21, 8.2%), index offense (30, 11.8%), and risk level (15, 5.9%). Participants were more likely to want risk level when given risk-irrelevant case histories or no summary likelihood statement than otherwise, p < .05, binomial tests. DISCUSSION

In this study of hypothetical decision making by forensic clinicians from a range of disciplines, estimated likelihood of violent recidivism was equally accurate (according to an objective index of violence risk) whether risk summary information was communicated using percentages or frequencies. Accuracy was unimproved by a case history relevant to risk accompanying a summary likelihood statement because such case information tended to increase the estimated likelihood of violent recidivism overall. Estimated likelihood of violent recidivism was very highly correlated with estimated comparative risk such that the two were treated as essentially identical. Decisions about security were strongly associated with estimated likelihood of risk. This study demonstrates that under some circumstances, forensic clinicians can

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use information related to violence risk. Furthermore, in their openended responses, participants indicated that they want to use such information. Only about a third of the variance in their recommended placement decisions, however, could be attributed to participants’ own estimates of the risk of violence posed by forensic patients. Other influences on security decisions appear to include an overly conservative tendency, particularly for higher risk cases. This is consistent with a recent report that judges tended to be conservative in hypothetical civil commitment decisions about psychiatric patients and more so with increased likelihood of violent recidivism by the patient such that many nonviolent persons would have been committed (Monahan & Silver, 2003). As well, cases in the present study without risk information were treated as though they were high risk. Adding risk-relevant case histories to summary likelihood statements compounded the perceived risk of violence in contrast to riskirrelevant histories. In the authors’ experiences, clinicians are more comfortable making decisions when they know offenders. Perhaps when case history was not redundant with the summary statement, participants felt they actually had more information, especially when none indicated high risk. Or perhaps clinicians begin with a conservative stance and information supporting such a stance increases conservatism, even if it is not true information in the sense of reducing uncertainty. The hypotheses about frequency statements being more effective than percentages were not confirmed and were even contradicted by the finding that a percentage summary statement yielded the best decision-making discrimination. Previous researchers (Slovic et al., 2000) concluded that estimation tasks are simplified by the use of frequencies. We suggest that a conclusive statement about risk itself simplifies the task for decision makers. That is, the present participants did not have to perform a mathematical procedure to estimate risk; they merely had to apply that risk to the case at hand. Just as the public got used to probability statements about weather (Murphy, 1991, as cited in Monahan & Steadman, 1996), forensic clinicians can become used to probabilistic statements about risk. Although our sample came from a single institution, we believe it serves to demonstrate that communicating actuarial risk information can be done optimally, obviating the need for “clinician-friendly” but statistically suboptimal


assessment. Further studies are required to examine the generalizability of the present findings to professionals in other settings. The materials in this study provided very limited case information. Even so, clinicians adjusted their estimates of risk according to the case history information provided. Research regarding human information processing indicates that only limited information can be handled, but the present study suggests that in the absence of a summary likelihood statement, risk-relevant case information can help violence risk assessment (if not risk management). On the other hand, when summary likelihood statements were provided, risk-relevant case information did not appear to improve decision making. Future studies could examine the effects of combining risk-relevant and riskirrelevant information as is typically encountered in real case histories. This study was unable to compare decision making as a function of discipline. It was felt that protection of anonymity was important in ensuring trust and frankness among participants who were few in number and often known to these authors. Members of all disciplines in the present facility make decisions about security, and ways to improve the communication of risk information to all was sought. These findings may generalize less to forensic settings in which psychiatrists or psychologists are the sole decision makers. At our facility, security recommendations by the multidisciplinary team are highly correlated with, but not identical to, recommendations made by the psychiatrist (Hilton & Simmons, 2001). In the future, comparing disciplines, or studying real risk-management decisions might illuminate communication methods best suited to other situations. It is acknowledged that forensic clinicians’ most preferred format for communicating risk is information about treatment, according to Heilbrun et al. (2000). The present study did not examine this option, instead testing information based on an empirically derived and empirically supported actuarial instrument for violence risk. The preference for risk-reduction strategies based on dynamic variables suggests that forensic psychologists, psychiatrists, and social workers want information that is not currently available from the empirical literature. Although there is empirical literature on effective interventions for adult offenders (see review by Harris & Rice, 1997), research

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linking interventions targeting changeable personal characteristics to reductions in violent outcome remains to be done (Monahan et al., 2001). In this study, manipulating information that clinicians wrongly believed to be relevant to risk was carefully avoided. It would be interesting to examine the effects of information about risk-relevant treatment needs (Andrews et al., 1990) on forensic decision making and their interaction with violence likelihood information. Previous surveys indicated clinicians also reported preferring categories of risk (e.g., high, low, medium) over more specific statements of the likelihood of violence (Heilbrun et al., 1999; Heilbrun et al., 2000). In contrast, the current finding that estimated likelihood of violence and comparative risk were highly correlated and an earlier finding that clinicians used probability scales as if they were comparative rating scales (Slovic & Monahan, 1995) suggest that clinicians do not distinguish absolute and comparative risk as implied by high, medium, and low categories. Although our participants generally said they used risk-relevant information when available, none who requested further information mentioned comparative risk or percentile rank. Furthermore, Monahan and Steadman (1996) demonstrated that high, medium, low statements of comparative risk were misleading or meaningless. Future research should examine the effect of percentile statements on forensic decisions. In the present study, the best decisions—the greatest distinction in security placement between objectively higher and lower risk patients—occurred when a probabilistic (percentage-based) risk assessment summary statement was provided. In the absence of actuarial risk information, participants tended to be conservative or even declined to make a decision. Although previous surveys indicated clinicians said they preferred not to have a summary statement about the likelihood of violence, this study suggests they make better decisions when such a statement is provided. The present study also implies that asking forensic clinicians what form of risk statement they prefer might not be the appropriate means to discover what method of communicating risk information leads to optimal decision-making performance. Surveys showed that people anticipated disliking weather forecasts using probability (e.g., a 30% chance of rain tomorrow) but quickly came to prefer them (Murphy, 1991, as cited in Monahan & Steadman, 1996). We concur with Monahan and Steadman (1996),


who concluded that percentile rank, probabilistic information, and a risk category can all be communicated in a single parsimonious statement. It is hoped this small study will stimulate further direct empirical research on how forensic decision making can be improved. APPENDIX A Sample Case Histories RISK-RELEVANT CASE HISTORY

Hugh is a 35-year-old maximum security patient. His parents separated during his childhood because of his father’s drinking problem. He had some attendance and discipline problems beginning in elementary school, and he started drinking at age 12. By the time he was 16, he would spend the weekends breaking into homes to steal alcohol and cash. He has a history of two charges for nonviolent offences and was charged with a breach of probation on one occasion. He was 17 when he committed his index offence, which resulted in the young male victim being hospitalized. He has never had a marital relationship. There is no evidence of any psychotic disorder. He has met the criteria for a DSM-III diagnosis of antisocial personality disorder, and his score on the Hare Psychopathy Checklist was 33. RISK-IRRELEVANT CASE HISTORY

Dave is a 35-year-old patient on a ward in Oak Ridge. He was born in a suburb of Toronto. He was the second oldest in a family of four boys. He is an experienced construction worker, and he likes to talk about the tree house he built when he was a teenager. His behavior has been unchanged since he first settled into Oak Ridge. He has regular visits with his mother and sister as well as occasional phone calls and letters. He is a short man and overweight, but staff report that he tries to eat a healthy diet. He has high cholesterol that is controlled by medication. He gets up early in the morning and is usually sleeping soundly soon after lock-up. He often needs reminders about his room, which gets cluttered and messy. He enjoys going out to yard whenever he can.

APPENDIX B Questionnaire Items On a scale from 1 to 100, how likely is this patient to reoffend violently within 10 years? How do you think his risk of violent reoffending compares with other forensic patients? (Make an X on the line like the example in the instructions)

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lower than higher than most patients_____________________________________________most patients What would you recommend at his preboard? (check one) [ ] stay in maximum security [ ] stay, but have an early review [ ] medium security, no community privileges [ ] medium security with community privileges [ ] minimum security [ ] release to community From the case scenario above, what factor(s) most affected your preboard recommendation?

REFERENCES Andrews, D. A., Zinger, I., Hoge, R. D., Bonta, J., Gendreau, P., & Cullen, F. T. (1990). Does correctional treatment work? A clinically relevant and psychologically informed meta-analysis. Criminology, 28, 369-404. Bélanger, N., & Earls, C. (1996). Sex offender recidivism prediction. Forum on Correctional Research, 8, 22-24. Bonta, J., Law, M., & Hanson, K. (1998). The prediction of criminal and violent recidivism among mentally disordered offenders: A meta-analysis. Psychological Bulletin, 123, 123142. Brace, G. L., Cosmides, L., & Tooby, J. (1998). Individuation, counting, and statistical inference: The role of frequency and whole-object representations in judgment under uncertainty. Journal of Experimental Psychology: General, 127, 3-21. Fuller, J., & Cowan, J. (1999). Risk assessment in a multi-disciplinary forensic setting: Clinical judgment revisited. The Journal of Forensic Psychiatry, 10, 276-289. Grann, M., Belfrage, H., & Tengström, A. (2000). Actuarial assessment of risk for violence: Predictive validity of the VRAG and the historical part of the HCR-20. Criminal Justice and Behavior, 27, 97-114. Grove, W. M., Zald, D. H., Lebow, B. S., Snitz, B. E., & Nelson, C. (2000). Clinical versus mechanical prediction: A meta-analysis. Psychological Assessment: A Journal of Consulting and Clinical Psychology, 12, 19-30. Hanson, R. K., & Harris, A. J. R. (2000). Where should we intervene? Dynamic predictors of sexual assault recidivism. Criminal Justice and Behavior, 27, 6-35. Hanson, R. K., & Thornton, D. (2000). Improving risk assessments for sex offenders: A comparison of three actuarial scales. Law and Human Behavior, 24, 119-136. Harris, G. T., & Rice, M. E. (1997). Mentally disordered offenders: What research says about effective service. In C. D. Webster & M. A. Jackson (Eds.), Impulsivity: Theory, assessment and treatment (pp. 361-393). New York: Guilford. Harris, G. T., Rice, M. E., & Cormier, C. A. (2002). Prospective replication of the Violence Risk Appraisal Guide in predicting violent recidivism among forensic patients. Law and Human Behavior, 26, 377-394.

Hilton et al. / COMMUNICATING RISK INFORMATION 115 Harris, G. T., Rice, M. E., & Quinsey, V. L. (1993). Violent recidivism of mentally disordered offenders: The development of a statistical prediction instrument. Criminal Justice and Behavior, 20, 315-335. Harris, G. T., Rice, M. E., Quinsey, V. L., Lalumière, M., Boer, D., & Lang, C. (2003). A multisite comparison of actuarial risk instruments for sex offenders. Psychological Assessment, 15, 413-425. Heilbrun, K., Philipson, J., Berman, L., & Warren, J. (1999). Risk communication: Clinicians’ reported approaches and perceived values. Journal of the Academy of Psychiatry and Law, 27, 397-406. Heilbrun, K., O’Neill, M. L., Strohman, L. K., Bowman, Q., & Philipson, J. (2000). Expert approaches to communicating violence risk. Law and Human Behavior, 24, 137-148. Hilton, N. Z., & Simmons, J. L. (2001). The influence of actuarial risk assessment in clinical judgments and tribunal decisions about mentally disordered offenders in maximum security. Law and Human Behavior, 25, 393-408. Kropp, P. R., & Hart, S. D. (2000). The Spousal Assault Risk Appraisal (SARA) Guide: Reliability and validity in adult male offenders. Law and Human Behavior, 24, 101-118. Litwack, T. R. (2001). Actuarial versus clinical assessments of dangerousness. Psychology, Public Policy, and Law, 7, 409-443. Mamuza, J. (2001). Do actuarial assessments fall victim to base rate neglect? Dissertation Abstracts International, 61(10), 5617B. Manktelow, K. (1999). Reasoning and thinking. Hove, UK: Psychology Press/Taylor & Francis. Monahan, J. (1996). Violence prediction: The past twenty and the next twenty years. Criminal Justice and Behavior, 23, 107-120. Monahan, J., Heilbrun, K., Silver, E., Nabors, E., Bone, J., & Slovic, P. (2002). Communicating violence risk: Frequency formats, vivid outcomes, and forensic settings. International Journal of Forensic Mental Health, 1, 121-126. Monahan, J., & Silver, E. (2003). Judicial decision thresholds for violence risk management. International Journal of Forensic Mental Health, 2, 1-6. Monahan, J., & Steadman, H. J. (1996). Violent storms and violent people: How meteorology can inform risk communication in mental health law. American Psychologist, 51, 931-938. Monahan, J., Steadman, H. J., Silver, E., Appelbaum, P. S., Clark Robbins, P., Mulvey, E. P., et al. (2001). Rethinking risk assessment: The MacArthur study of mental disorder and violence. New York: Oxford University Press. Polvi, N. H. (2001). The relative efficacy of statistical versus clinical predictions of dangerousness (Simon Fraser University, Department of Psychology, 2001). Dissertation Abstracts International, 61(7). Price, R. (1997). On the risks of risk prediction. The Journal of Forensic Psychiatry, 8, 1-4. Quinsey, V. L., & Ambtman, R. (1979). Variables affecting psychiatrists’ and teachers’ assessments of the dangerousness of mentally ill offenders. Journal of Consulting and Clinical Psychology, 47, 353-362. Quinsey, V. L., Coleman, G., Jones, B., & Altrows, I. E. (1997). Proximal antecedents of eloping and reoffending among supervised mentally disordered offenders. Journal of Interpersonal Violence, 12, 794-813. Quinsey, V. L., Harris, G. T., Rice, M. E., & Cormier, C. A. (1998). Violent offenders: Appraising and managing risk. Washington, DC: American Psychological Association. Rice, M. E., & Harris, G. T. (1995). Violent recidivism: Assessing predictive validity. Journal of Consulting and Clinical Psychology, 63, 737-748. Rice, M. E., & Harris, G. T. (1997). Cross validation and extension of an actuarial instrument for the prediction of violent recidivism. Law and Human Behaviour, 21, 231-241.

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Schwarz, N. (1999). Self-reports: How the questions shape the answers. American Psychologist, 54, 93-105. Slovic, P., & Monahan, J. (1995). Probability, danger, and coercion: A study of risk perception and decision making in mental health law. Law & Human Behavior, 19, 49-65. Slovic, P., Monahan, J., & MacGregor, D. G. (2000). Violence risk assessment and risk communication: The effects of using actual cases, providing instruction, and employing probability versus frequency formats. Law & Human Behavior, 24, 271-296. Sykes, D. L., & Johnson, J. T. (1999). Probabilistic evidence versus the representation of an event: The curious case of Mrs. Prob’s dog. Basic and Applied Social Psychology, 21, 199212. Taylor, P. J., Goldberg, E., Leese, M., Butwell, M., & Reed, A. (1999). Limits to the value of mental health review tribunals for offender patients. British Journal of Psychiatry, 174, 164-169. Webster, C. D., Douglas, K. S., Eaves, D., & Hart, S. (1997). HCR-20: Assessing Risk for Violence, Version 2. Burnaby, BC: Mental Health, Law and Policy Institute.