Drug misuse prevention: targeted interventions

Recommendations 1.1.1 and 1.1.2

The committee heard expert testimony that the focus of commissioning new drug misuse prevention interventions is changing [EP1]. Many areas are increasingly integrating drug misuse prevention activities with drug treatment or wider health and social care activities, such as activities to increase general resilience and decrease risky behaviours within sexual health services or educational support services to address truancy [EP1].

The committee acknowledged that the misuse of substances such as illegal drugs and alcohol rarely happens in isolation. Many people at increased risk of drug misuse may already be in contact with statutory, voluntary or private services such as mental health, community-based criminal justice, alcohol and drug services, and services for children and young people who are looked after and care leavers. The committee heard expert testimony that local authorities are well placed to address the wider needs of some groups at risk, such as their housing needs [EP1]. However, local authorities also need to collaborate with wider services, such as healthcare services, schools, or police and crime commissioners, to provide effective drug misuse prevention activities [EP1].

The committee noted that none of the interventions included in the health economic modelling were cost effective as stand-alone programmes (see overview of the cost-effectiveness evidence) [ES4.1, ES4.2, ES4.3, ES4.4, ES4.5, ES4.6, ES4.7]. However, they could be cost effective if added to existing programmes of care at an additional cost of less than £100 per person [ES4.9].

Taking into account the changing focus of commissioning, wider determinants of drug use and the health economic modelling, the committee recommended that drug misuse prevention interventions should be delivered through a range of existing services for people in groups at risk, rather than setting up dedicated services.

Recommendation 1.2.1

The committee discussed assessing whether people are vulnerable to drug misuse. The committee agreed that it was essential to have an assessment before intervention to ensure that the intervention offered is appropriate and no harm is done. It noted that an assessment of drug use was a consistent part of effective interventions included in evidence review 1. No studies were identified that included an assessment only arm compared with assessment plus intervention and no intervention. However, the committee discussed that if comparator groups were offered assessment, improved drug or other outcomes were consistently reported. The committee also noted that there was weak evidence from review 2 that assessments of substance use and other risky behaviours may prompt reductions in drug use [ES2.22].

The committee noted that none of the 7 interventions modelled by the health economic team were cost effective in the base case as a stand-alone intervention (see overview of the cost-effectiveness evidence) [ES4.1, ES4.2, ES4.3, ES4.4, ES4.5, ES4.6, ES4.7]. The committee noted from the health economic modelling that to be cost effective an intervention would need to cost less than £100 per person and would need to reduce the number of people misusing drugs by at least 5 percentage points over 2 years [ES4.8]. The committee agreed that a reduction of at least 5 percentage points in the number of people at risk of misusing drugs was most likely to occur in people who are assessed as vulnerable to drug misuse. As such, interventions are likely to be cost effective only in people who are vulnerable to drug misuse.

The committee discussed that interventions that target people assessed as most vulnerable to drug misuse are more likely to be cost effective. The committee agreed that drug misuse prevention activities cannot be targeted to people most vulnerable to drug misuse if those people have not been assessed. It noted that undertaking assessment before an intervention is consistent with the related NICE guideline on psychosocial interventions for drug misuse in people aged 16 years and older.

The assessment could be part of either a routine appointment (such as health needs assessments for children and young people who are looked after) or an opportunistic appointment (such as when someone attends an emergency department as a result of alcohol use, or when young people come into contact with the community-based criminal justice system). Many different practitioners may be working with people at risk of drug misuse. These practitioners have an important role in identifying people who may benefit from drug misuse prevention activities, even if the practitioners do not provide drug misuse prevention activities themselves. The committee therefore recommended that routine and opportunistic appointments provided by statutory and other services should be used to assess vulnerability to drug misuse.

The committee agreed that all practitioners who have contact with people in groups at risk, including practitioners working in health services, social care services and the criminal justice system, should be aware of drug misuse prevention and should use every contact to identify those at risk.

Recommendation 1.2.2

The committee was not able to recommend a particular assessment tool for a number of reasons. The committee noted that most tools that are available focus on people who already use drugs rather than those at risk of misusing drugs. Comments from stakeholders during consultation on the draft guideline highlighted several assessment tools that stakeholders believed could be useful. However, the committee noted that these tools may not fit easily into routine and opportunistic appointments provided by statutory and other services. Some of the tools focused on alcohol use rather than drug use. The committee was aware that there is no single tool that is suitable for use in all groups at risk and for assessing all vulnerabilities. It was concerned that recommending a tool for a particular group at risk may result in the tool being used with other groups at risk, which may not be appropriate. The committee noted evidence that whatever approach is chosen, it should be non-judgemental, which is likely to be more acceptable to participants [ES2.17, ES2.20, ES2.32]. So the committee was unable to recommend a specific assessment tool, but recommended that a consistent, locally agreed, respectful and non-judgemental approach is used.

The committee recommended that the approach for assessment should be proportionate to the person's presenting vulnerabilities. The committee noted that the assessor may become more aware of potential vulnerabilities through their discussion with the person and may therefore need to do a more intensive assessment to explore these vulnerabilities.

The committee noted that there are existing practice standards for young people with substance misuse problems from the Royal College of General Practitioners, Alcohol Concern, DrugScope and Royal College of Psychiatrists. The overall quality of the practice standards document was rated as 5 out of 7 using the AGREE II tool, where 1 indicates 'lowest possible quality' and 7 indicates 'highest possible quality'. The practice standards document scored well on several domains in the tool, including being clear on the aim of the guideline and its target population, involving stakeholders throughout development, presenting recommendations clearly, and providing information on implementation. It did not score as well on describing how the evidence was selected, the strengths and limitations of the evidence, or the methods for formulating the recommendations. However, this information can be found in the guidance (including NICE guidance) that the recommendations in the practice standards document are based on. The committee noted that there is no corresponding practice standards document for adults. However, it believed that many of the practice standards were relevant for adults as well as young people. The committee agreed that the practice standards are a useful example of an approach for assessing a person's vulnerability to drug misuse.

Recommendation 1.2.3

The committee discussed the importance of an assessment considering how the wider health and personal context, such as a person's age and developmental stage, as well as their personal, social, health, mental health and educational or employment circumstances, may affect their vulnerability to drug misuse. It also discussed the importance of assessment addressing the possible harm associated with any existing drug use by that person.

The committee recommended that assessors should be aware that the person's circumstances may be complex. The committee acknowledged that people working with groups at risk need to have an understanding of the potential vulnerabilities to drug misuse. They should also be aware that people may present with more than 1 vulnerability, and that people who do present with more than 1 vulnerability may be at increased risk of drug misuse.

The committee agreed that an assessment might identify people who are already misusing drugs. As previously noted, it can be difficult to make a distinction between occasional or recreational use and regular or excessive use. The committee highlighted that the definition of 'excessive use' is subjective and may vary depending on the individual (for example, their age and developmental stage) and their circumstances. For example, drug use that is not considered excessive in an adult may be considered excessive in a younger person.

Treatment of people who use drugs or alcohol regularly or excessively is outside the scope of this guideline. NICE has guidelines on psychosocial interventions and opioid detoxification for drug misuse in people aged 16 years and older, diagnosis and management of alcohol-use disorders in people aged 10 years and older, and needle and syringe programmes for adults and young people, including those under 16.

Recommendation 1.2.4

The committee discussed the role of safeguarding. It acknowledged that safeguarding includes protecting vulnerable people of any age from physical and emotional maltreatment, sexual abuse, neglect and exploitation. It agreed that safeguarding is everyone's responsibility. It added that all practitioners who are in contact with vulnerable people have a duty to protect them from maltreatment and share information with other services.

The committee agreed that practitioners undertaking assessment of whether someone is vulnerable to drug misuse should be aware that the assessment may raise safeguarding concerns. It acknowledged that safeguarding concerns may become more apparent to the practitioner once the assessment has ended and they are reflecting on the discussion. Although the committee emphasised the importance of safeguarding, it acknowledged that recommending referral to specialist services, such as child protection services, as a result of safeguarding concerns is outside the scope of the current guideline.

The committee also acknowledged that not all concerns need immediate intervention from social care services, and that other factors (such as problems at school) may have a larger effect on the person's vulnerability to drug misuse. The committee therefore recommended that the assessor should think about whether there are concerns for the safety of the person being assessed and any people under their care.

Recommendation 1.2.5

The committee recommended that people undertaking assessments should discuss the person's priorities and consider what effect their priorities have on prevention activities or referral to specialist services. The committee highlighted that there are existing practice standards for young people with substance misuse problems from the Royal College of General Practitioners, Alcohol Concern, DrugScope and the Royal College of Psychiatrists.

Recommendation 1.3.1

The committee noted that the health economic team modelled 7 drug misuse prevention interventions. None of these were cost effective in the base case as a stand-alone intervention (see overview of the cost-effectiveness evidence) [ES4.1, ES4.2, ES4.3, ES4.4, ES4.5, ES4.6, ES4.7].

The committee noted from the health economic modelling that to be cost effective, an intervention would need to cost less than £100 per person and would need to reduce the number of people misusing drugs by at least 5 percentage points over 2 years [ES4.8]. The committee agreed that a reduction of at least 5 percentage points in the number of people at risk of misusing drugs was most likely to occur in people who are assessed as vulnerable to drug misuse. As such, interventions are likely to be cost effective only in people who are vulnerable to drug misuse. The committee recommended that interventions are prioritised for those with increased vulnerability.

Evidence for the effectiveness of offering personal and social skills training to children and young people at risk of drugs misuse and to their parents and carers came from 4 studies reported in 4 papers [Esc]. Two trials reported a significant reduction in drug use, including a trial undertaken with children and young people who are looked after and their foster carers. There was also evidence from 3 studies of a significant improvement in personal and social skills after skills training for children and young people and their parents or carers, which supports the studies that found a significant reduction in drug use.

One of the trials of personal and social skills training for children and young people and their parents and carers reported an increase in cannabis use in children and young people who underwent skills training. However, the committee believed this finding could be a result of participants changing their drug use from other drugs to cannabis during the study, because the study also reported a decrease in the use of drugs other than cannabis. An additional study did not report a significant reduction in drug use after the intervention; however, in this study drug use was measured immediately after the intervention only and no longer-term data were collected.

The committee noted that there was evidence from evidence review 2 that group-based skills training [ES2.33, ES2.46] and opportunistic skills training, advice and information provision are acceptable to participants [ES2.39]. However, it also acknowledged that it may not be appropriate to include carers or families in all cases, such as if children have been sexually abused.

Personal and social skills training for only children and young people who are vulnerable to drug misuse was not recommended because the evidence was limited and inconsistent [ESa]. Two studies of the effectiveness of skills training for children and young people showed an inconsistent effect on drug use, with the use of some drugs being significantly reduced but the use of other drugs not changing significantly. A third study reported no difference in drug use after skills training for children and young people. One study reported a significant improvement in drug refusal skills, problem-solving skills, and coping skills after the intervention. Another study concluded that skills training for children had no significant effect on feelings of self-worth, but it did not report data, p values or an effect size. One study reported that the intervention may have affected intention to use drugs, but the data were not reported. Another study reported a statistically significant improvement in knowledge of drugs and their risks after the intervention with peer educators but not with adult educators.

Personal and social skills training for only carers and families of children and young people at risk of drug misuse was not recommended. This was because it was not clear that skills training for parents and carers alone had a significant effect on drug use in the children and young people they cared for. Evidence for the effectiveness of skills training for parents or carers came from 4 trials reported in 7 papers [ESb]. One trial and 2 follow-up studies reported no statistically significant difference in drug use. Three trials and a secondary analysis of one of the trials reported significantly reduced drug use after the intervention. However, 2 of the trials that reported significantly reduced drug use included other interventions for the families in addition to skills training, such as case management, weekly family therapy, individual therapy, and motivational interviewing. It is not clear whether the skills training or the other interventions had a significant effect on drug use.

Family-based interventions as a whole were not recommended because they were unlikely to be cost effective for the populations included in the current guideline. The committee acknowledged the evidence on family-based interventions showed a mixed effect on drug use, with 5 studies in 6 papers showing a significant reduction in drug use, 4 studies in 6 papers showing no significant effect on drug use, and 1 study showing a significant increase in drug use [ES1.50]. However, the committee noted that the evidence base included studies of Multidimensional Treatment Foster Care and motivational interviewing, which are more intensive than skills training alone. The committee was aware that family-based interventions were recommended in NICE's guideline on substance misuse interventions for vulnerable under 25s. It noted that this recommendation included motivational interviewing and family therapy, which were very unlikely to be cost effective for the populations included in the current guideline.

The health economic modelling looked at 3 family-based interventions that included skills training [ES4.1, ES4.3, ES4.7]. None of the interventions were found to be cost effective in the base case scenario. However, the committee noted that these interventions involved other activities as well as skills training, such as motivational interviewing, which would have made them more costly. The committee noted that the results of the modelling showed that 2 of the interventions could be cost effective if the cost of delivering them was lower and the effects of the interventions could be sustained over 2 years or more [ES4.3, ES4.7]. It also noted that interventions could be made cost effective if they were added to existing programmes of care at an additional cost of less than £100 per person [ES4.9].

Manualised and licensed programmes, of which 4 out of5 were family-based, were not recommended because they were costly and may not be effective for the populations included in the current guideline. The committee noted that evidence review 1 included studies of manualised and licensed programmes, namely Focus on Families [ES1.10], Family Competence Program [ES1.11], Multidimensional Treatment Foster Care [ES1.14, ES1.18], Familias Unidas [ES1.17] and Free Talk [ES1.19]. The studies either showed no significant effect on drug use [ES1.10, 1.19], an inconsistent effect on drug use [ES1.14, ES1.18] or did not report drug use outcomes [ES1.11]. The committee noted that such programmes are costly and that adapting programmes to make them cost less than £100 per person could have an impact on effectiveness. The committee also noted that none of the studies of manualised and licensed programmes were from the UK, and it is not clear whether the programmes would have the same effectiveness in a different country from where the study was performed. The committee concluded that it could not recommend adapting existing manualised or licensed drug misuse prevention programmes for use in the UK.

Motivational interventions were not recommended because of the uncertainty in the terminology and the effectiveness and cost-effectiveness evidence. The evidence review identified 3 main types of motivational intervention: 'motivational interviewing'; 'brief interventions'; and 'motivational enhancement therapy' (see evidence tables for details of the interventions). The committee noted that most studies did not clearly describe the intervention and used terminology that may not match the committee's understanding. It acknowledged that the programme development group for NICE's guideline on individual approaches to behaviour change noted similar issues. The programme development group concluded that it was not possible to recommend motivational interviewing because the studies did not specify which principles and components were used. The committee therefore considered the evidence for motivational interventions as a whole.

The committee noted that there were 15 unique trials of motivational interventions, of which 9 were in children and young people [ESe, ESf, ESg]. Two of the 9 trials reported significant reductions in drug use. However, 1 of these trials showed a significant difference in the use of some drugs at some time points but not others, and the other trial showed reduced drug use in some contexts but not others. The committee agreed that, overall, motivational interventions were unlikely to be significantly more effective than skills training.

The committee discussed the health economic modelling for motivational interventions. It showed that motivational interviewing was not cost effective in the base case, ranging from £131,000 per QALY gained to £485,000 per QALY gained [ES4.4, ES4.5, ES4.6]. The modelling showed that motivational interviewing would only be cost effective if it could be delivered for less than £190 and could reduce drug use for at least 2 years [ES4.4, ES4.5, ES4.6]. The committee agreed that motivational interventions were unlikely to be cost effective compared with skills training.

Taking into account the uncertainty in the terminology and the effectiveness and cost-effectiveness evidence, the committee concluded that it was unable to recommend motivational interventions for groups at risk of drug misuse. The committee recommended that research is undertaken in this area (see research recommendation 3).

The committee agreed that skills training for children and young people as well as for their carers or families was likely to be a more cost-effective way to reduce the risk of drug misuse than family-based interventions or manualised or licensed programs, and motivational interventions for children and young people. This is because it is more likely that skills training could be delivered as part of existing services for less than £100 per person. The committee noted that skills training is likely to improve a range of outcomes, including those that are not related to drug misuse. It did not believe there was enough evidence to recommend skills training just for children and young people, or just for their carers and families. The committee reiterated that any skills training should be delivered as part of existing services, as in recommendation 1.1.1.

The committee discussed the different groups of people that this guideline is relevant to. It acknowledged that services aimed at groups at risk use different ages to distinguish between child and adult services. For example, specialist services for drug treatment aimed at adults may include people aged 16 and over, whereas services for children and young people that are looked after may include those aged up to 25. The committee was aware that 'young people' can include people with a range of ages and developmental stages. It acknowledged that for some young people it may be more appropriate to offer skills training, and for other young people it may be more appropriate to offer information on drugs and their effects. The committee recommended that following an assessment of whether a young person in a group at risk is vulnerable to drug misuse, the most appropriate prevention options for that young person should be considered.

Recommendation 1.3.2

The committee agreed that integrating skills training for children and young people and their carers and families into existing services could lower the additional cost of the interventions and therefore be a cost-effective way to deliver drug misuse prevention interventions. The committee heard expert testimony that integrating skills training into existing services is becoming a more common approach [EP1].

Based on the cost-effectiveness evidence, the committee recommended that skills training for children or young people and their carers or families should be commissioned as part of existing services (see discussion section on recommendation 1.2.1).

The committee noted that skills training is likely to be delivered by people who do not work in drug and alcohol services. It agreed that any skills training should be delivered by people who are already competent to provide it, instead of investing resources in training people to deliver it. It noted that the NICE guideline on antisocial behaviour and conduct disorders in children and young people includes recommendations on the training and competencies of staff working with children and young people.

Recommendations 1.3.3 and 1.3.4

The committee discussed the content of skills training sessions, noting that different approaches were used in different studies and that most studies included training on more than 1 type of skill. The skills training interventions for children and young people that successfully reduced the risk of drug use and improved personal and social skills included skills such as listening, conflict resolution and refusal. Other components of effective skills training interventions were identifying and managing stress, making decisions, coping with criticism, dealing with feelings of exclusion, and making healthy behaviour choices [ES1.7, ES1.8, ES1.11, ES1.13, ES1.15, ES1.21, ES1.23].

The committee noted that the skills training interventions for parents and carers of children at risk of drug use that successfully reduced the risk of drug use and improved personal and social skills included skills such as communication, developing and maintaining healthy relationships, conflict resolution, and problem solving [ES1.11, ES1.13, ES1.15, ES1.17, ES1.21, ES1.23, ES1.57, ES1.58, ES1.60]. The committee recommended that skills training should aim to develop a range of skills, with the skills used in the studies as examples.

The committee agreed that skills training for children and young people who are looked after and care leavers, and their carers, needed particular consideration, because there was clearer evidence of the success of skills training for this group compared with other groups. Successful skills training interventions for children and young people who are looked after and care leavers included social skills and how to deal with feelings of exclusion [ES1.13]. For foster carers, the important component was how to use behaviour reinforcement systems [ES1.13, ES1.14]. The committee recommended that skills training for children and young people who are looked after, care leavers and foster carers emphasised these skills.

Recommendations 1.3.5 and 1.3.6

The committee discussed the wide variation in age and developmental stage in the groups at risk. The committee noted that skills training sessions can be used for people of different ages; however, sessions aimed at a young child might not be appropriate for a young adult. The committee recommended that age and developmental stage should be taken into account when deciding on the details of the skills training sessions.

The committee considered other aspects that might influence the effectiveness of skills training offered to children and young people. It agreed that presenting vulnerabilities, cultural context, religion and ethnicity may be important. It recommended that these factors be taken into account, along with any other specific needs or preferences of the child or young person vulnerable to drug misuse, when deciding the details of what training sessions to provide. It also noted the evidence that interventions should be made engaging, relevant and creative [ES2.12, ES2.18].

The committee considered whether interventions should be provided one-to-one or in a group-based setting. It acknowledged there was mixed evidence for the effectiveness of group-based behaviour therapy (including skills training) for children and young people [ES1.54], but that it is generally well received [ES2.13]. The committee agreed that group-based skills training is likely to cost less per person than one-to-one skills training. None of the studies looked at the effectiveness of one-to-one skills training, but the committee acknowledged that group environments may not be appropriate for everyone in groups at risk. The committee recommended taking into account the child or young person's needs and preferences when deciding whether sessions should be provided one-to-one or in groups.

The committee considered the number and duration of skills training sessions that should be delivered. It acknowledged that the overall effectiveness of family-based interventions did not appear to vary by the intensity or duration of the intervention [ES1.68]. However, it was not clear whether this was also true for the subset of family-based interventions that included skills training sessions for children or young people and their parents or carers. Studies used different numbers (3 to 14 sessions) and durations of training sessions (from not reported to 1.5 to 2 hours), and the committee noted no consistent pattern of effectiveness.

The committee felt unable to recommend a specific number or duration of sessions. However, it acknowledged that skills training is likely to be offered as part of a larger programme, in which skills related to drug misuse prevention may be a small part of each training session. Therefore, the committee recommended that skills training should consist of 2 sessions as a minimum. The committee recommended taking the needs of the child or young person into account when determining the number and duration of skills training sessions. It also recommended discussing and agreeing a plan for follow-up at the skills training sessions to determine whether additional skills training or referral to specialist services is needed.

The committee also considered where skills training interventions should be delivered. It noted evidence that participants reported having access to a trusted setting in which they are surrounded by likeminded peers could stop them misusing drugs [ES2.19]. The committee recommended that the settings in which skills training will be delivered should also be considered.

The committee was unable to recommend details of the skills training, such as where to hold the sessions, as this information was not available from the evidence. However, the committee was aware that the Department of Health has published quality criteria for young people friendly services. It recommended that these criteria are used for information when considering skills training for children and young people.

Recommendation 1.4.1

The committee noted that the health economic team modelled 7 drug misuse prevention interventions. None of these were cost effective in the base case as a stand-alone intervention (see overview of the cost-effectiveness evidence) [ES4.1, ES4.2, ES4.3, ES4.4, ES4.5, ES4.6, ES4.7].

The committee noted from the health economic modelling that to be cost effective, an intervention would need to cost less than £100 per person and would need to reduce the number of people misusing drugs by at least 5 percentage points over 2 years [ES4.8]. The committee agreed that a reduction of at least 5 percentage points in the number of people at risk of misusing drugs was most likely to occur in people who are assessed as vulnerable to drug misuse. As such, interventions are likely to be cost effective only in people who are vulnerable to drug misuse, and the committee recommended that interventions are prioritised for those with increased vulnerability.

The committee was unable to recommend skills training for adults at risk of drug misuse because the evidence was limited [ESd]. The committee noted that only 1 study of skills training for adults at risk of drug misuse reported significantly reduced drug use compared with before the intervention. The committee acknowledged there was mixed evidence for the effectiveness of group-based skills training as a whole; however, it noted that this evidence included studies in children and young people at risk of drug misuse, as well as adults [ES1.42].

Motivational interventions were not recommended because of the uncertainty in the terminology and the effectiveness and cost-effectiveness evidence. The evidence review identified 3 main types of motivational intervention: 'motivational interviewing', 'brief interventions' and 'motivational enhancement therapy' (see evidence tables for details of the interventions). The committee noted that most studies did not clearly describe the intervention and used terminology that may not match the committee's understanding. It acknowledged that the programme development group for NICE's guideline on individual approaches to behaviour change noted similar issues. The programme development group concluded that it was impossible to recommend motivational interviewing because the studies did not specify which principles and components were used. The committee therefore considered the evidence for motivational interventions as a whole.

The committee noted that there were 15 unique trials of motivational interventions, of which 6 were in adults [ESe, ESf, ESg]. Of these 6 trials, 3 trials reported significant reductions in drug use. One trial showed a significant reduction in drug use compared with no assessment or intervention, but no significant reduction in drug use compared with education or information.

The committee discussed the health economic modelling for motivational interventions. It showed that motivational interviewing was not cost effective in the base case, ranging from £131,000 per QALY gained to £485,000 per QALY gained [ES4.4, ES4.5, ES4.6]. The modelling showed that motivational interviewing would only be cost effective if it could be delivered for less than £190 and could reduce drug use for at least 2 years [ES4.4, ES4.5, ES4.6]. The committee agreed that motivational interventions were unlikely to be cost effective compared with other interventions or current practice.

Taking into account the uncertainty in the terminology and the effectiveness and cost-effectiveness evidence, the committee concluded that it was unable to recommend motivational interventions for groups at risk of drug misuse. The committee recommended that research is undertaken in this area (see research recommendation 3).

The committee was unable to recommend skills training or motivational interventions for adults who are assessed as vulnerable to drug misuse; however, it wanted to recommend some action should be taken. The committee agreed it should provide recommendations on what current practice involves. The committee considered what current practice involved in studies that found current practice to be as effective as motivational interventions [ES1.2, ES1.22, ES1.36, ES1.37]. Current practice was found to include brief information and education on drugs and their effects (such as health and social effects), and feedback. The committee recommended that adults who are assessed as vulnerable to drug misuse should receive these components of current practice. It also recommended research in this area (see research recommendation 2).

The committee considered whether additional components should be added to the care of adults who are vulnerable to drug misuse. It agreed that information on sources of advice or support would be helpful for adults at increased risk. The committee agreed that information and advice should be offered at the time of their assessment.

Recommendation 1.4.2

The committee considered whether the information and advice offered to adults assessed as vulnerable to drug misuse should be provided in a verbal or written format. The committee acknowledged the evidence from 1 study that participants did not find written information as useful as verbal information [ES2.27] and they thought it was outdated [ES2.31]. However, it noted that this may not be true for all written information and that written information can be useful for people who want to revisit information in their own time. The committee noted the evidence that participants stressed the value of being able to ask questions, and this is only likely to happen when information is provided verbally [ES2.31]. The committee therefore recommended that information and advice is provided in a written and verbal format.

The committee considered factors that may affect the provision of information to adults who are vulnerable to drug misuse. It discussed the different levels of understanding about health across groups of people. It noted that the level of understanding about health is likely to vary widely among adults who are vulnerable to drug misuse. The committee also noted that NICE's guideline on patient experience in adult NHS services recommends taking people's general literacy levels into account to meet their needs. The committee agreed that the person's level of understanding about health needs to be considered when providing information to adults who are vulnerable to drug misuse.

The committee noted evidence that a non-judgemental approach to providing advice was more acceptable to participants [ES2.17, ES2.20, ES2.32]. It therefore recommended using a respectful and non-judgemental approach.

The committee noted that NICE has existing guidance on general and individual approaches to behaviour change. It recommended that information and advice is provided in line with these guidelines.

Recommendation 1.4.3

The committee considered the number of information sessions needed for adults who are vulnerable to drug misuse. It agreed that the approach used to provide information will need to vary to account for the wide range of adults who are vulnerable to drug misuse. The committee recommended that a plan for follow-up is discussed and agreed at the time of the person's assessment (see recommendation 1.2.1).

Recommendation 1.5.1

The committee discussed the groups at risk that may not present to health or social care services. Committee members heard expert testimony that people who use image- and performance-enhancing drugs are less likely to present because they may not identify as drug users [EP2]. They noted that people in some of the groups at risk may not be in contact with health or social care services (for example, people who go to nightclubs and festivals, people who are homeless, people who go to gyms, and children and young people at school) [EP2] or may be in contact only with wider health services, such as sexual and reproductive health services. People may also avoid seeking advice because much drug use involves illegal drugs [EP2].

Recommendations 1.5.2 and 1.5.3

The committee considered what drug misuse prevention services could be offered to people in groups at risk who do not present to health or social care services. Digital technologies can allow interventions to be offered to people who are either unable or choose not to access services, and can offer anonymity. The committee noted the evidence showed that web-based interventions did not significantly reduce drug use [ES1.48] compared with assessment only [ES1.32, ES1.33] or a waiting list control [ES1.34]. However, 1 study did show promising effects of web-based information and advice in a subgroup analysis of people with a family history of drug problems [ES4.2]. Web-based interventions were generally well received [ES2.29, ES2.30, ES2.41].

The health economic modelling did not find web-based interventions to be cost effective in the base case (£329,000 per QALY). If an intervention was delivered at a cost of less than £1 per person, it would be less costly and more effective than a 'do nothing' alternative [ES4.2].

The committee considered that web-based interventions could feasibly be produced at a low cost and was aware of existing online sources of information, including NHS Choices. It noted that the NHS Choices website provides reliable information and also provides links to other helpful sources of information. The committee therefore recommended that targeted new media (including web-based information as well as digital and social media), that give reliable information, and online self-assessment and feedback to help people assess their own drug use, could be provided to people at increased risk. These approaches may be particularly useful in those less likely to be in contact with health and social care services. The committee also recommended that further research should be undertaken on the effectiveness of digital technologies (see research recommendation 5).

The committee noted that some people in groups at risk may not be able to access online services. It recommended that written information should be made available for people not in contact with health or social care services.

The committee also recommended that information given to people not in contact with health or social care services should include information on local services and sources of advice and support.

Recommendation 1.5.4

The committee noted that NICE has existing guidance on general and individual approaches to behaviour change. It recommended that information is provided to people at risk of using drugs in line with these guidelines.

Limitations of the effectiveness and acceptability evidence

The committee noted that most of the included studies used small sample sizes, short follow-up times, self-reported drug use and intermediate outcomes (such as knowledge about drugs, rather than change in drug-using behaviour). It was not possible to determine whether some studies were poorly conducted or poorly reported. Some studies may not have been adequately powered to identify significant differences between groups. In addition, some participants in some studies did not attend any of the intervention sessions, and many studies did not include a true control group. As a result, the efficacy of the intervention could have been underestimated in these studies.

The committee noted that single small studies were presented for more than 1 group at risk, resulting in multiple evidence statements from the same studies. This makes the evidence base look larger and stronger than it actually is. Overarching evidence statements have been used to summarise the body of evidence across population groups [ESa, ESb, ESc, ESd, ESe, ESf].

The committee acknowledged that limited evidence was available on the effectiveness of interventions in the UK. Most interventions considered were undertaken in the US. Although the evidence is likely to be applicable in the UK, the committee discussed that key differences in social norms, education, care, and criminal justice and healthcare systems may influence the effectiveness of interventions transferred to UK settings. In addition, the committee noted that the comparators included in the studies may vary from those seen in the UK. It also agreed that current practice (referred to in the studies as 'standard care') was not well defined or consistently reported in the studies. Current practice can vary depending on which group at risk is included in a study, and the country and setting in which the study was conducted.

The committee discussed that some of the interventions in the studies were likely to have been delivered in a research setting; for example, a university research facility. It was felt that the results may have been different if the interventions had been delivered in real-world settings, such as homeless shelters, nightclubs or music events, youth clubs and organisations, or environments where drugs may be used in a sexual context (such as 'chemsex' parties).

The committee agreed that the group 'people who are known to use drugs occasionally or recreationally' represents a diverse population. Although several studies were identified for this group, it is likely that the evidence does not cover the whole target population.

The committee noted that no good quality evidence is available for some groups at risk, despite the research recommendations made in NICE's previous guideline on substance misuse interventions for vulnerable under 25s. Committee members agreed that more evidence from well designed and adequately powered studies is needed. The committee recommended that research is undertaken on the effectiveness and acceptability of drug misuse prevention interventions in groups at risk (see research recommendation 3 and research recommendation 4).

The committee noted that studies of pregnant women were excluded from the evidence reviews for this guideline. There is existing NICE guidance on pregnancy and complex social factors, which includes substance misuse in pregnant women. General antenatal and postnatal care is covered in existing NICE guidance. In addition, it was agreed that studies on drug use in pregnant women are most likely to be studies of treatment for dependent drug users rather than prevention studies.

Limitations of the cost-effectiveness evidence

The studies used in the health economic modelling were identified in the evidence review. Therefore, the limitations of the studies in the evidence review also apply to the cost-effectiveness evidence.

The committee noted that the effect on someone of having a criminal record was not taken into account in the health economic modelling. It acknowledged that drug use can lead to a criminal record, and that people with a criminal record have difficulties securing employment. Therefore, avoiding a criminal record is a potential positive outcome of drug misuse prevention activities. It agreed that including the effect on an individual of having a criminal record in the health economic modelling would have increased the cost effectiveness of the interventions.

The committee also recognised that the long-term harms and associated costs of drug use are mostly unknown. The size of the groups at risk is unknown, and it is not known what percentage of people in these groups will go on to misuse drugs. These factors will affect the accuracy of the health economic modelling. The committee therefore recommended research is done on the long-term consequences of drug use (see research recommendation 1).

Terminology

The committee discussed that many terms used in the literature to describe drug use are subjective and often used inconsistently or interchangeably (for example, terms such as 'use', 'misuse', 'occasional' or 'recreational', 'dependency' and 'abuse'). It discussed that the definition of 'recreational' use in particular was subjective. For example, fortnightly use of cannabis by an adult might be considered recreational, but fortnightly use by a child or young person may be considered problematic.

The committee discussed the term 'primary care'. It acknowledged that the use of the term by the public focuses on general practitioners. However, the committee agreed that the use of the term in this guideline includes all primary care services, including healthcare professionals such as pharmacists, dentists and optometrists.

Although treatment for drug misuse fell outside the remit of this guideline, there is an overlap between treatment, harm reduction (aiming to prevent or reduce negative effects of drugs) and prevention in this field. Despite careful consideration by 3 reviewers, some studies of harm reduction interventions may have been misinterpreted as treatment studies and so would not have been considered in this guideline. The committee noted that NICE has a range of products that cover drug misuse, and in particular that treatment has been considered by related NICE guidelines (psychosocial interventions and opioid detoxification for drug misuse in people aged 16 years and older).