Home > HRB publishes review of reviews .

Galvin, Brian (2017) HRB publishes review of reviews . Drugnet Ireland, Issue 63, Autumn 2017, pp. 13-14.

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In 2015, the Health Research Board (HRB) commissioned the Public Health Institute at Liverpool John Moores University to prepare a report on the most recent international evidence on responses to problem drug use. This was to support the steering committee working on a new drugs strategy. Incorporating evidence into policy has been a concern of several countries developing drugs strategies in recent years. Part of this process is identifying responses that have been shown to work but, just as importantly, identifying what evidence is relevant to the national situation, where the gaps in evidence are, and what interventions are shown not to be effective or produce harmful results.


Ensuring that a strategy is evidence based requires an acknowledgement that evidence is constantly improving and knowledge on effective responses will develop during the term of the strategy. A dynamic strategy supports this development and recognises the value of the evidence produced by the evaluative process built into responses.


In July 2017, the HRB published The effectiveness of interventions related to the use of illicit drugs: prevention, harm reduction, treatment and recovery. A ‘review of reviews’.1 The ‘review of reviews’ approach provides an overview of the most recent high-quality evidence. The primary research questions for the review were: 

  • Which interventions are effective in reducing the initiation, or continued use, of illicit drugs and related harmful behaviours among children and young people aged up to 25 years?
  • Which interventions are effective in reducing harmful behaviours related to illicit drug use?
  • Which interventions are effective in treating drug misuse among people who misuse or who are dependent upon illicit drugs?
  • Which interventions are effective in supporting people who misuse illicit drugs to fully recover from their illicit drug misuse and become better reintegrated into the community following/alongside treatment? 

Using the reviews to answer questions on responses in the drugs area

It is helpful to separate the findings of the reviews into what is known to work or not work and interventions of unproven efficacy thus far. This makes the findings quickly apparent. But demonstrating the scientific value of the work somewhat hides the value of the ‘review of reviews’ approach and its role in the development of an evidence baseline relevant to the Irish situation.


Below are some examples of how the review might be used to answer questions that are of interest to stakeholders.


Question 1: How can young people be enabled to make sensible decisions about substance use or provide help to members at risk of abusing drugs or affected by drug use?


Family-based programmes are one of the most commonly used approaches internationally to prevent substance misuse in young people. These interventions can be aimed at all individuals (parents and young people) or just parents in a range of settings. Information on the harms of drug use and sessions on effective parenting, communication and discipline typically feature on these programmes. Currently, in Europe, those interventions involving the whole family are more likely to be recommended than those that train parents only.


Findings from high-quality and medium-quality studies in the prevention review suggest that a combined parent-and-child-intervention approach may be more effective at reducing cannabis initiation and use than interventions that target parents alone. Moderate-quality review level evidence from the treatment review suggests that multidimensional family therapy is effective for reducing drug use frequency and severity in comparison to other interventions among adolescents, including cognitive behavioural therapy (CBT), but is generally no more nor less effective for treatment retention.


Question 2: How do you reduce the risk of harm from drugs in a recreational setting, such as a nightclub?


High-quality evidence in the harm reduction review suggests that effective harm reduction activities in a recreational setting include staff training, law enforcement, user/patron prevention and harm reduction interventions. No evidence was identified on pill-testing kits or similar interventions for inclusion in this review, reflecting the lack of evidence available (at primary or review level) on this approach.


Question 3: How can treatment programmes increase the likelihood of reintegration and recovery?


The researchers were asked to pay particular attention to this topic, as it was anticipated that this would be of interest in the development of the strategy. With this in mind, they looked at reviews prior to 2010 and lower-quality reviews.


Medium-quality and low-quality evidence on recovery and reintegration interventions in the treatment reviews section of the report indicates that peer coaching, recovery housing, and mutual aid approaches may have benefits for substance use outcomes. Moderate-quality evidence indicates that residency in recovery homes was associated with improved employment, reduced criminal behaviour and substance use in comparison to ‘usual care’ treatments, but evidence on these outcomes was limited. Evidence indicated that peer-recovery coaching interventions were associated with reduced substance use in comparison to individuals receiving usual aftercare, but this evidence was limited by the quality of review and primary study evidence. There was moderate-quality evidence to suggest that continuing care may have a positive effect on substance use in comparison to control treatments.


Question 4: How can evaluation be integrated into comprehensive community-based programmes aimed at preventing both licit and illicit substance use?


Measuring the effectiveness of a prevention intervention is difficult. As Germany’s National strategy on drug and addiction policy (2012)2 states:


The goal of prevention is to avoid the occurrence of an event, whether this means the initial consumption of a substance, the emergence of abusive behaviour or addiction. Monitoring success therefore involves measuring the non-occurrence of an event. This is the main reason why the evaluation of prevention measures is one of the most difficult areas to evaluate in terms of methodology.2 (p. 16)


The review identified a number of reviews of well-defined and rigorous programmes. Adapting programmes of this type locally presents challenges. However, the reviews included in the study also identify the outcomes used to measure the effectiveness of a prevention programme.


A review from 2006 indicated that comprehensive community-based programmes are more effective than school or community-only-based interventions at preventing both licit and illicit substance use. This review listed a number of primary and secondary outcomes that were measured by the evaluations, including in this systematic review. This is useful in identifying outcomes which could be included in an evaluation of programmes of this type being implemented locally. 


  • Primary outcomes: Numbers of people who stop using substances
  • Frequency of substance use
  • Numbers of people who start using substances
  • Time before initiation of substance use 

Secondary outcomes:

  • Changes in pattern of substance, range of substances, or type of substance
  • Changes in risk or protective factors: – Knowledge – Attitudes towards drug use – School attendance – Family cohesion – Access to services
  • Outcomes identified in various health programmes
  • Engagement of community of vulnerable young people in the programme
  • Drug-related illnesses
  • Outcomes related to criminal justice system: – Prosecutions – Changes in antisocial or offending behaviour – Outcomes identified in criminal justice programmes aimed at children  

Using the reviews to identify gaps in the evidence

The review identifies gaps in the evidence and areas where further exploration is needed. We can only determine which evidence gaps are relevant when it is decided what questions need to be answered. There are several areas covered by the review where the evidence is inconclusive. This may because of the low number of studies in this area, the lack of quality evaluations, or the quality of the reviews that have looked at these evaluations. A decision on whether to support a particular intervention should not be based solely on the evidence available in a high-level review. There will always be responses for which we do not have strong evidence to support them. That is the nature of this type of work. This presents an opportunity to contribute to the knowledge base on an intervention using carefully constructed evaluations. Many of the studies included in reviews, while not presenting conclusive evidence, can support this process, as they will have identified appropriate outcomes which can be used to measure the effectiveness of the response.


Psychosocial treatments

It is good practice to provide access to evidence-based and well-designed psychosocial interventions (based on behavioural, cognitive, motivational and social theories) in addition to standard care or in conjunction with existing pharmacological drug treatments. The review provides evidence of effectiveness on many types of psychosocial treatments, including the following interventions:


Brief interventions (Prevention review): While evidence on the effectiveness in drug prevention is scarce, there is substantial evidence to suggest that brief interventions may be effective in alcohol prevention. Brief interventions are applied to recreational users or individuals at risk of misusing drugs; however, for individuals, who are already misusing substances, a brief intervention may not be appropriate or sufficient to change an established behaviour.


Cognitive behavioural therapy (Treatment review): Moderate-quality evidence suggested that CBT is generally more effective for outcomes relating to cannabis use and dependency in comparison to individuals receiving no treatment, but no more nor less effective than other interventions. When combined with contingency management, low-quality evidence on the effectiveness of CBT was mixed and inconclusive in comparison to other interventions.


Couples-based therapy (Treatment review): Moderate-quality review evidence indicates that couples-based interventions are more effective than relapse-prevention CBT for achieving abstinence.


Multisession psychosocial interventions (Harm reduction review): Moderate-quality evidence suggests that multisession psychosocial interventions aimed at people who inject drugs may have beneficial impacts on sexual risk behaviours, but not on injection risk behaviours. Evidence regarding behavioural interventions was limited and based on small numbers of primary studies.


Interventions for people who come in contact with the criminal justice system

There is good evidence for only a limited number of interventions in this setting. However, contact with the criminal justice system through arrest, probation or incarceration presents opportunities for preventative and harm reduction interventions. These can complement existing treatments:


HIV risk reduction (Harm reduction review): Moderate-quality evidence indicates that improving accessibility to HIV testing through onsite testing in probation and immediate next day testing in prison is associated with an increased uptake of HIV testing.


Psychosocial interventions in prison (Treatment review): There is some evidence to suggest that treatment through prison-based therapeutic communities reduces drug relapse and criminal activity among prisoners. There is no consistent evidence to support other treatment types for this population, including drug courts, boot camps and psychosocial interventions, although there was limited and low-quality review level evidence supporting meditation-based treatment.


1 Bates G, Jones L, Maden M, Cochrane M, Pendlebury M, Sumnall H (2017) The effectiveness of interventions related to the use of illicit drugs: prevention, harm reduction, treatment and recovery. A ‘review of reviews’. Dublin: Health Research Board. https://www.drugsandalcohol.ie/27253/

2 Drug Commissioner of the Federal Government (2012) National strategy on drug and addiction policy. Berlin: Drug Commissioner of the Federal Government [Die Drogenbeauftragte der Bundesregierung]. Available online at http://www.drogenbeauftragte.de/


Trends analysis of drugs situation in Ireland

The Health Research Board commissioned the Public Health Institute at Liverpool John Moores University to prepare a trends analysis on the drugs situation in Ireland. The drugs situation in Ireland: an overview of trends from 2005 to 20151 reviews the current drug situation in Ireland, analysing 10 years of data up to the most recent data available, with respect to the five European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) key indicators (prevalence of drug use, high risk drug use, treatment demand, drug-related deaths, and mortality and drug-related infectious diseases) as well as drug-related crime and supply. In addition to presentation of national trends, this report includes additional evidence looking at trends in data relating to specific subpopulations, including people who inject drugs, prisoners, homeless individuals, sex workers and the Traveller community.


1 Bates G (2017) The drugs situation in Ireland: an overview of trends from 2005 to 2015. Liverpool: Public Health Institute, Liverpool John Moores University. https://www.drugsandalcohol.ie/27254

Item Type
Publication Type
Irish-related, International, Open Access, Article
Drug Type
All substances
Intervention Type
Treatment method, Alternative medical treatment, Harm reduction, Psychosocial treatment method, Rehabilitation/Recovery
Issue Title
Issue 63, Autumn 2017
November 2017
Page Range
pp. 13-14
Health Research Board
Issue 63, Autumn 2017

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