A systematic review of risk assessment strategies for populations at high risk of engaging in violent behaviour: update 2002-8.

BACKGROUND: This review systematically examines the research literature published in the period 2002-8 on structured violence risk assessment instruments designed for use in mental health services or the criminal justice system. It adopted much broader inclusion criteria than previous reviews in the same area in order to capture and summarise data on the widest possible range of available instruments. OBJECTIVES: To address two questions: (1) what study characteristics are associated with a risk assessment instrument score being significantly associated with a violent outcome? and (2) which risk assessment instruments have the highest level of predictive validity for a violent outcome? DATA SOURCES: Nineteen bibliographic databases were searched from January 2002 to April 2008, including PsycINFO, MEDLINE, Cumulative Index to Nursing and Allied Health Literature, Allied and Complementary Medicine Database, British Nursing Index, International Bibliography of the Social Sciences, Education Resources Information Centre, The Cochrane Library and Web of Knowledge. REVIEW METHODS: Inclusion criteria for studies were (1) evaluation of a structured risk tool; (2) outcome measure of interpersonal violence; (3) participants aged 17 years or over; and (4) participants with a mental disorder and/or at least one offence and/or at least one indictable offence. A series of bivariate analyses using either a chi-squared test or Spearman's rank-order correlation were conducted to explore associations between study characteristics and outcomes. Data from a subset of studies reporting area under the curve (AUC) analysis were combined to provide estimates of mean validity. RESULTS: For the overall set of included studies (n = 959), over three-quarters (77%) were conducted in the USA, Canada or the UK. Two-thirds of all studies were conducted with offenders who had either no formal mental health diagnosis (43%) or forensic samples with a formal diagnosis (25%). The Psychopathy Checklist-Revised was tested in the largest number of studies (n = 192). Most studies (78%) reported a statistically significant (p < 0.05) relationship between the instrument score and a violent outcome. Prospective data collection (chi-squared = 4.4, p = 0.035), number of people recruited (U = 27.8, p = 0.012) and number of participants at end point (U = 26.9, p = 0.04) were significantly associated with predictive validity. For those instruments tested in five or more studies reporting AUC values, the General Statistical Information on Recidivism instrument had the highest mean AUC (0.73). LIMITATIONS: Agreement between pairs of reviewers in the initial pilot exercises was good but less than perfect, so discrepancies may be present given the complexity and subjectivity of some aspects of violence research. Only five of the seven calendar years (2003-7) are completely covered, with partial coverage of 2002 and 2008. There is no weighting for sample or effect sizes when results from studies are aggregated. CONCLUSIONS: A very large number of studies examining the relationship between a structured instrument and a violent outcome were published in this relatively short 7-year period. The general quality of the literature is weak in places (e.g. over-reliance on cross-sectional designs) and a vast range of distinct instruments have been tested to varying degrees. However, there is evidence of some convergence around a small number of high-performing instruments and identification of the components of a high-quality evaluation approach, including AUC analysis. The upper limits (AUC ≥ 0.85) of instrument-based prediction have probably been achieved and are unlikely to be exceeded using instruments alone. FUNDING: The National Institute for Health Research Health Technology Assessment and Research for Patient Benefit programmes.

A systematic review of prevention and intervention strategies for populations at high risk of engaging in violent behaviour: update 2002-8.

BACKGROUND: It has been estimated that violence accounts for more than 1.6 million deaths worldwide each year and these fatal assaults represent only a fraction of all assaults that actually occur. The problem has widespread consequences for the individual and for the wider society in physical, psychological, social and economic terms. A wide range of pharmacological, psychosocial and organisational interventions have been developed with the aim of addressing the problem. This review was designed to examine the effectiveness of these interventions when they are developed in mental health and criminal justice populations. OBJECTIVE: To update a previous review that examined the evidence base up to 2002 for a wide range of pharmacological, psychosocial and organisational interventions aimed at reducing violence, and to identify the key variables associated with a significant reduction in violence. DATA SOURCES: Nineteen bibliographic databases were searched from January 2002 to April 2008, including PsycINFO (CSA) MEDLINE (Ovid), Cumulative Index to Nursing and Allied Health Literature (CINAHL), Allied and Complementary Medicine Database (AMED), British Nursing Index/Royal College of Nursing, International Bibliography of the Social Sciences (IBSS), Education Resources Information Center (ERIC)/International ERIC, The Cochrane Library (Cochrane reviews, other reviews, clinical trials, methods studies, technology assessments, economic evaluations), Web of Science [Science Citation Index Expanded (SCIE), Social Sciences Citation Index (SSCI), Arts & Humanities Citation Index (A&HCI)]. REVIEW METHODS: The assessment was carried out according to accepted procedures for conducting and reporting systematic reviews, including identification of studies, application of inclusion criteria, data extraction and appropriate analysis. Studies were included in meta-analyses (MAs) if they followed a randomised control trial (RCT) design and reported data that could be converted into odds ratios (ORs). For each MA, both a fixed-effects model and a random-effects model were fitted, and both Q statistic and I2 estimates of heterogeneity were performed. RESULTS: A total of 198 studies were identified as meeting the inclusion criteria; of these, 51 (26%) were RCTs. Bivariate analyses exploring possible sources of variance in whether a study reported a statistically significant result or not, identified six variables with a significant association. An outcome was less likely to be positive if the primary intervention was something other than a psychological or pharmacological intervention, the study was conducted in an penal institution, the comparator was another active treatment or treatment as usual and if a between-groups design had been used. An outcome was more likely to be positive if it was conducted with people with a mental disorder. The variation attributable to these variables when added to a binary logistic regression was not large (Cox and Snell R(2) = 0.12), but not insignificant given the small number of variables included. The pooled results of all included RCTs suggested a statistically significant advantage for interventions over the various comparators [OR 0.59, 95% confidence interval (CI) 0.53 to 0.65, fixed effects; OR 0.35, 95% CI 0.26 to 0.49 random effects, 40 studies]. However, there was high heterogeneity {I(2) = 86, Q = 279 [degrees of freedom (df) = 39], p < 0.0001}, indicating the need for caution in interpreting the observed effect. Analysis by subgroups showed that most results followed a similar pattern, with statistically significant advantages of treatments over comparators being suggested in fixed- and/or random-effects models but in the context of large heterogeneity. Three exceptions were atypical antipsychotic drugs [OR 0.21, 95% CI 0.16 to 0.27, fixed effects; OR 0.24, 95% CI 0.14 to 0.43, random effects; 10 studies, I(2) = 72.2, Q = 32.4 (df = 9), p < 0.0001], psychological interventions [OR 0.63, 95% CI 0.48 to 0.83, fixed effects; OR 0.53, 95% CI 0.31 to 0.93, random effects; nine studies, I(2) = 62.1, Q = 21.1 (df = 8), p = 0.007] and cognitive behavioural therapy (CBT) as a primary intervention [OR 0.61, 95% CI 0.42 to 0.88, fixed effects; OR 0.61, 95% CI 0.37 to 0.99, random effects; seven studies, I(2) = 21.6, Q = 7.65 (df = 6), p = 0.26]. LIMITATIONS: The heterogenity of the included studies inhibits both robust MA and the clear application of findings to establishing improvements in clinical practice. CONCLUSIONS: Results from this review show small-to-moderate effects for CBT, for all psychological interventions combined, and larger effects for atypical antipsychotic drugs, with relatively low heterogeneity. There is also evidence that interventions targeted at mental health populations, and particularly male groups in community settings, are well supported, as they are more likely to achieve stronger effects than interventions with the other groups. Future work should focus on improving the quality of evidence available and should address the issue of heterogenity in the literature. FUNDING: The National Institute for Health Research Health Technology Assessment programme and the Research for Patient Benefit programme.

The clinical effectiveness and cost-effectiveness of central venous catheters treated with anti-infective agents in preventing bloodstream infections: a systematic review and economic evaluation.

OBJECTIVES: To assess the clinical effectiveness and cost-effectiveness of central venous catheters (CVCs) treated with anti-infective agents in preventing catheter-related bloodstream infection (CRBSI). DATA SOURCES: Major electronic databases were searched from 1985 to August 2005. REVIEW METHODS: The systematic clinical and economic reviews were conducted according to accepted procedures. Only full economic evaluations (synthesis of costs and benefits) comparing the use of anti-infective central venous catheters (AI-CVCs) with untreated CVCs or other treated catheters were selected for inclusion in the economic review. RESULTS: A total of 32 trials met the clinical inclusion criteria. Seven different types of AI-CVC were identified, with the most frequently tested being chlorhexidine and silver sulfadiazine (CHSS) (externally treated), CHSS (externally and internally treated) and minocycline rifampicin (internally and externally treated). In general, the trials were of a poor quality in terms of reported methodology, microbiological relevance and control of confounding variables. The pooled result suggests a statistically significant advantage for AI-CVCs in comparison to standard catheters in reducing CRBSI [odds ratio (OR) 0.45, 95% confidence interval (CI) 0.34 to 0.60, 24 studies, I-squared = 0%, fixed effects]. Analysis by subgroups of catheters demonstrates that antibiotic-treated catheters and catheters treated internally and externally decrease CRBSI rates significantly (OR 0.26, 95% CI 0.15 to 0.46, six studies, I-squared = 0%, fixed effects, and OR 0.43, 95% CI 0.26 to 0.70, nine studies, I-squared = 0%, fixed effects, respectively). Catheters treated only externally demonstrate a wider CI and non-significant effect (OR 0.67, 95% CI 0.43 to 1.06, nine studies, I-squared = 0%, fixed effects). A treatment effect was also found for trials with an average duration of between 5 and 12 days, and for the one study with a mean duration of over 20 days. There was a statistically significant treatment effect for both femoral and jugular insertion sites and for those studies reporting a mix of insertion sites. The treatment effect was not observed in trials using exclusively subclavian insertion sites. Of the four trials that compared treated catheters, one reported a benefit of antibiotic-treated catheters over catheters treated externally with CHSS. All three sensitivity analyses testing for study design differences reported a statistically significant treatment effect. The review was limited owing to the quality of the trials included, marked differences in the definitions and methods of diagnosis of CRBSI, and inconsistent reporting of risk factors and patient population factors. Furthermore, two-thirds of trials were commercially funded. The economic performance (cost-effectiveness and potential cost-savings) of using AI-CVCs to reduce the number of CRBSIs in patients requiring a CVC was also reviewed. Results show that the use of AI-CVCs instead of standard CVCs can lead to a reduction in CRBSIs and decreased medical costs. To complement the reviews, a basic decision-analytic model was constructed to explore a range of possible scenarios for the NHS in England and Wales. Results show that for every patient who receives an AI-CVC there is an estimated cost-saving of 138.20 pounds. The multivariate sensitivity analyses estimate potentially large cost-savings, depending on the size of the population, under a wide range of cost and clinical assumptions. However, those considering the purchase of AI-CVCs should ensure that their patient populations and the important characteristics of local clinical practice are indeed similar to those described in this economic evaluation. CONCLUSIONS: Overall, AI-CVCs are clinically effective and relatively inexpensive and therefore their integration into clinical practice can be justified. However, the use of these anti-infective catheters without the appropriate use of other practical care initiatives will have only a limited success on the prevention of CRBSIs. Comparative trials are required to determine which, if any, of the treated catheters is the most effective. Pragmatic research related to the effectiveness of bundles of care that may reduce rates of CRBSI is also warranted.