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EXECUTIVE SUMMARY

Aims

1 The remit of this review was to provide a comprehensive overview of the known effectiveness of interventions aimed at preventing suicide, suicidal behaviour and suicidal ideation, both in key risk groups and in the general population. Whilst not restricted to the Scottish context, one goal of the review was to evaluate the evidence available to inform the prevention of suicide in Scotland. The review was commissioned by the (then) Scottish Executive Health Department in 2005 and is now being published by the Scottish Government as part of a programme of research work, in support of its commitment to suicide prevention and in taking forward the Choose Life National Strategy and Action Plan to Prevent Suicide in Scotland (Objective 7 in the strategy related to 'knowing what works'). This commission followed a scoping exercise which identified the need for a review of interventions. To address this need, the research team carried out a wide-ranging systematic review of the available evidence. The review evaluated both quantitative and qualitative evidence for the effectiveness of interventions. Any and all interventions for which research evidence could be found were included within the remit of the review. The review represents the most comprehensive overview of the intervention literature currently available.

Specific objectives

2 The specific objectives of the review were as follows:

• Identify the interventions which have been evaluated to date
• Summarise the conclusions which can be drawn from the literature as it stands, taking into account the quality of available data
• Highlight key defining features of the interventions evaluated to date
• Specify the known impact of interventions, taking into account the populations and settings to which these apply
• Address the cost-effectiveness of interventions where such data are available
• Consider the transferability of effective interventions to the Scottish context and examine the implications for implementation and replication
• Identify gaps in the evidence base
• Make evidence-based recommendations for the development of national and local policy and practice, identifying variations in strategic approach for different key risk groups

3 All of the above objectives have been addressed. However, the available research evidence was not suited to providing answers to all of the questions posed within these objectives. There is, for example, very little evidence available regarding the cost-effectiveness of particular interventions. Since the effectiveness even of the most promising interventions largely remains to be established this is perhaps unsurprising. However, this clearly presents a problem for service providers with limited resources to allocate and a clear remit to reduce existing rates of suicide and self-harm. Similarly, there is very little evidence specific to the Scottish context. The available evidence overall also tends to be fairly non-specific both in terms of the defining features of interventions, which are rarely discussed in the empirical literature, and in respect of the demographic or other population characteristics of study participants, which are poorly reported in the literature.

4 It is not possible, given the current state of the evidence, to model adequately the likely impact of transferring interventions to the Scottish context. However, there is to date also little reason to believe that the more 'generic' interventions, such as the provision of ongoing contact or provision of telephone support would differ in their impact on distinct populations. Finally, in respect of recommendations for key risk groups, it is clear that the approach of the literature to date has been rather more eclectic than is desirable from the viewpoint of the practitioner or policy maker. Few studies have evaluated interventions developed explicitly for 'high risk' groups and where such groups have been the focus of intervention research, they tend not to match the priority groups identified by national prevention initiatives in Scotland or in England and Wales. Where the review is able to make substantive recommendations is in respect of the gaps within the current evidence base, the means by which future research could significantly improve the evidence base and, in relation to the evidence which is currently available, the merits of particular forms of intervention based on the quality of the available evidence.

Methods

5 The review process followed the 'gold standard' for systematic review methodology set out by the Cochrane Collaboration and by the NHS Centre for Reviews and Dissemination. However, it differed from many of the reviews which have been produced using this method in the breadth and depth of its search strategy. The remit of the review was to include evidence relating to any evaluated intervention regardless of the research methods used, the population, setting or other foci of the pertinent studies. This broad-ranging approach offers several advantages over more 'traditional' systematic reviews, not least of which is the opportunity to compare outcomes across settings, populations, modes of intervention and modes of suicidal behaviour and ideation. The citation database generated for the review also provides an extensive repository of available evidence which can be further explored to address issues in research and practice not specifically addressed within the remit of the current report.

6 The review was restricted to searches conducted using electronic databases. Eighteen separate databases were searched, including primary research databases, specialist and secondary research databases and databases accessing the 'grey' (largely unpublished) literature. Whilst the only restrictions on the initial citations retrieved were that they had to address interventions for suicidal behaviour or suicidal ideation, additional criteria were imposed on the citations to be included within the review report. Specifically, research reports had to be written in the English language, to present evidence from an 'empirical' study (broadly defined to include any attempt at quantitative or qualitative evaluation) and to focus on 'intentional' behaviour, with interventions for non-intentional self harm in people with learning disabilities or conditions such as Lesch Nyhan's disease excluded.

7 The initial search process identified 26,085 citations relevant to intervention for suicidal behaviour and suicidal ideation. Using restriction terms to identify empirical evaluations of interventions reduced this total to 8,606 citations. Two reviewers then screened the abstracts of each of these citations to exclude material not meeting the core criteria for the review report. This reduced the number of citations meeting our criteria to 646. All 646 studies were screened by two reviewers in full-text format and from this process we identified 200 primary empirical studies and 37 prior systematic reviews meeting the criteria for the review. These studies form the basis of the evidence presented in this report.

Overview of retrieved material

8 The review identified a number of methodological issues relating to the existing research evidence which need to be addressed if future research is to successfully inform evidence-based practice. It also identified a number of concerns regarding the extent and focus of the current evidence base. Research to date has adopted a 'scatter-gun' approach, with a very small number of studies each addressing one of a very broad and diverse range of interventions. This has resulted in an evidence base poorly suited to meeting the immediate needs of either practitioners or policy makers seeking to prevent suicidal behaviours and ideation. Populations which are particularly poorly served by the available literature are people engaged in (currently) non-fatal self-harm, in particular self-cutting; people at either end of the age spectrum (those younger than 15 or older than 65); and people from social, cultural and ethnic minority populations. Socio-economic status has also been given little attention in the intervention literature.

9 Overall, the quality of available research in this field compares favourably with that of research addressing other broadly comparable public health issues such as other-directed violence (Leitner et al 2006). However, the evidence base does suffer from certain methodological failings which are commonly attributed to actual or perceived ethical and pragmatic constraints on research into suicidal behaviour and ideation. In particular, a failure to randomise participants to treatment and 'control' conditions, to 'blind' investigators and, where relevant, participants, to treatment allocation and a failure to control for the impact of other ongoing but un-evaluated 'background' interventions. Additional methodological concerns include high drop-out rates and a lack of attention to the adequacy of implementation of interventions.

10 The majority of the available evidence derives from studies carried out on US or Canadian populations. However, there is an international focus to the literature with 21 countries contributing to the current evidence base. In contrast to many other public health literatures, the UK has contributed a substantive amount of evidence, accounting for 19% of primary empirical studies. We were, however, able to identify only 5 independent studies of interventions for suicidal behaviour or ideation which had been carried out on Scottish populations.

11 Other concerns regarding the 'coverage' of the available research evidence relate to the populations and settings in which research has been carried out. There is a clear tendency in the literature to associate suicidal behaviour with mental illness. Nearly half (46%) of the available research evidence focuses on interventions for psychiatric populations. In particular, the research focuses on people with depression or with borderline personality disorder. Whilst mental illness has been identified as an important risk factor, this imbalance in the available evidence exaggerates the association and, as a consequence, comparatively little is known about interventions for the general population. In contrast, the majority of research studies have focussed on interventions carried out in community settings, with comparatively little evidence regarding intervention in institutional (e.g. school or prison) settings or in the broad range of available health care settings. Intervention in the Accident & Emergency setting is particularly under-researched, despite the fact that this setting represents the main point of first contact with health services for many people at risk of suicide.

Impact of interventions on suicidal behaviour and suicidal ideation

12 The most prominent focus of the literature to date has been on pharmaceutical intervention. However, the broad range of individual pharmaceutical interventions evaluated show a rather chequered profile in terms of outcome, with few indicators of consistent positive impact. Even commonly used pharmaceutical interventions such as anti-depressant treatment demonstrate a rather equivocal profile in terms of their impact on reductions in suicidal behaviour and ideation. There is evidence from a number of studies that the use of lithium in bipolar disorder may reduce attempted and completed suicide. However, concerns deriving from one study, that lithium increased the likelihood of suicide overall and from an additional high quality study that discontinuation of lithium treatment increased risk argue for caution in implementing the treatment in the absence of further high quality confirmatory studies. There is currently little evidence of any effective pharmaceutical intervention for self-harm. Suicidal ideation has been the preferred focus of a comparatively high proportion of pharmaceutical studies and there is some evidence from higher quality studies that the treatment of depression using fluvoxamine and sertraline may reduce suicidal ideation.

13 Equivocal outcomes for pharmaceutical intervention may account for a growing trend in the research literature to focus on the evaluation of non-pharmaceutical interventions. Whilst, to date, these have fared little better than pharmaceutical intervention, the emerging evidence base does point more consistently to some promising avenues for intervention. In respect of completed suicide, the available studies, including a limited number of higher quality studies, consistently point to a reduction in completed suicide following restrictions in the access to means and also following the maintenance of ongoing contact with the suicidal person. There is some evidence that service provision via specialist centres with highly trained personnel may also reduce rates of completed suicide. Consistent reductions in attempted suicide have been shown following a restriction in the access to means ¹ and following the setting up of informal social support for the suicidal person, although these outcomes are taken from a very small number of studies.

14 The use of individualised and intensive cognitive and behavioural therapies has shown particular promise in respect of reductions in attempted suicide and self-harm. The best evaluated of such therapies to date are Cognitive Behaviour Therapy ( CBT) and Dialectical Behaviour Therapy ( DBT), with the latter finding more consistent support within the literature, notably in the context of treatment for borderline personality disorder. There is currently little evidence relating to the effectiveness or otherwise of non-pharmaceutical interventions for suicidal ideation. The evidence which does exist presents only equivocal support for the use of CBT in this context. There is some limited evidence from higher quality studies that suicidal ideation may be reduced, over the short-term at least, by the use of telephone-based support, with non-interventionist/non-directive styles of communication demonstrating a greater impact on reductions in suicidal ideation.

Considerations for future research and practice

15 It is important to recognise that a lack of evidence of effectiveness is not the same as evidence that an intervention does not work. Very few interventions to date have been evaluated by more than a very small number of studies and the number of high quality studies available is even smaller. Although the methodological approaches adopted by the available literature are relatively sophisticated in comparison with many fields of health research, clear methodological failings are nevertheless evident and need to be addressed in future research.

16 Of particular concern is the fact that not one of the evaluated interventions had been pursued fully from the start point of theoretical development through to full scale long-term 'real world' implementation, as recommended by the Medical Research Council ( MRC, Campbell 2000). Whilst this report attempts to identify the most promising interventions given the evidence which is currently available, it is important that the lack of extensive and robust evidence is addressed. A well-funded, co-ordinated programme of research could go a long way towards improving the effectiveness of interventions for suicidal behaviour and ideation. Focussing initially on those interventions which find some support in the existing literature is likely to be the most cost-effective approach to driving forward the research base.

17 Many of the interventions which have shown promise to date are either not currently provided within the mainstream of service provision (e.g. long-term ongoing contact following discharge, support in developing social support networks) or are not available to the majority of people presenting with suicidal behaviours because services are over-subscribed (e.g. DBT). The most common form of intervention (pharmaceutical intervention), although it is also the most extensively evaluated, finds only equivocal support in the available literature. This picture may be improved by targeting the more promising forms of pharmaceutical intervention on population sub-groups for which there is some evidence of effectiveness (as with current studies evaluating the use of lithium in bipolar disorder and sertraline in depression). However, with emerging evidence that both minimalist interventions (such as ongoing contact) and intensive individualised therapies (e.g. DBT) show consistent evidence of effectiveness, there are clear incentives to focus future research initially on these comparatively novel and potentially cost-effective approaches. Future research could, for example, usefully evaluate which components of such therapies are of particular value and for which groups.

18 Considering the platform for service delivery, services for people showing suicidal behaviour or ideation in the UK are not currently structured around the model of specialist service provision (via dedicated centres or teams) which the literature suggests may be the most promising model of service delivery. Also at the broader, national, level, the most prominent forms of general population prevention initiatives (public information and school-based educational initiatives) are both under-evaluated and lacking in robust evidence of effectiveness where they have been evaluated. It may be that over time both the general nature of prevention and service provision and specific approaches to service provision for suicidal behaviour and ideation need to be re-considered and re-structured in line with outcomes from the developing evidence base. In the short-term however, it is essential that a co-ordinated approach to the research evaluation of both the structure of service provision and of the more promising interventions is put in place. Currently the 'scatter-gun' approach to research and the resulting fractured picture of intervention hinders any systematic approach to implementing evidence-based practice either in respect of the platform for service delivery or in respect of the interventions themselves.

19 In the absence of a fully developed evidence base, current recommendations for practice need to focus on those approaches for which there is both the most consistent support and the least evidence of potential harm to the client. Following this approach, the review provides some evidence that both relatively 'low key' interventions such as maintaining ongoing contact or supporting people in the development of social networks and short, intensive, cognitive interventions with a behavioural component (e.g. DBT) may be of benefit. At the broader level of national initiatives, the most promising interventions may be legislation aimed at restricting the access to means, service provision co-ordinated through specialist centres and provision of telephone-based or other centres to support the maintenance of ongoing contact with people at risk of suicidal behaviour.

20 We recommend that, in an effort to increase the evidence base as rapidly as possible, practitioners and researchers collaborate in the evaluation of ongoing interventions using routine data collated across the full range of clinical, community and institutional settings. This will be a challenging task, notably given current constraints on the use of patient information, but it is a necessary strategy, since the likelihood of individual research studies significantly increasing the current evidence base in the short term is slim. Future prevention strategies could be significantly improved by the routine collection of accurate and detailed cross-service information relating to presentations for self-harm.

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