In January 2017, Public Health England (PHE)1 published An evidence review of the outcomes that can be expected of drug misuse treatment in England.2 PHE was commissioned by the Department of Health in England to ‘review the evidence on: what can be expected of the drug treatment and recovery system and provide advice to inform future policy’ (p. 12). To meet this aim, they covered a number of topics related to drug treatment in England:

• The nature and prevalence of drug misuse and how drug treatment evolved to address it
• The outcomes achieved to date by the treatment system
• The international literature on treatment effectiveness and how England compared to other countries
• How housing, unemployment and social deprivation impact on treatment outcomes
• The changing profile of the drug treatment population
• How to improve treatment outcome measures 

A recurring theme throughout the report was that ‘indicators that are used to manage and commission drug treatment can have a powerful impact on how services are developed and on how resources are allocated locally’ (p. 115). The authors therefore called for ‘caution’ (p. 132) when selecting indicators to ensure the risk of generating unintended consequences was minimised. Indeed, they noted that indicators can be used to positively affect outcomes.

Approach to the review

The work was overseen by an expert reference group made up of a variety of stakeholders: academics, service commissioners and providers, and experts by experience (service users). PHE took a mixed methods approach to the review: they used focus groups with service users; statistical analysis of the National Drug Treatment Monitoring System data; and a series of evidence reviews using a rapid evidence assessment method.

Treatment outcomes in the literature

In their review of the international literature, the authors found that a broad range of outcomes were used to measure treatment effectiveness. These included drug use; abstinence; drug injecting; overdose; mental and physical health; mortality; crime; and social functioning indicators such as employment, housing, family relations, and service users’ perceptions of their recovery. The breadth of these measures was taken to reflect the broad range of harms caused by drug misuse and, in turn, the benefits that could be expected by users entering treatment and addressing their drug use. In terms of the cost-effectiveness of treatment, estimates in the literature suggested a net benefit‒cost ratio of approximately 2.5 to 1. For every £1 spent on treatment, there was a £2.50 benefit to society.

Social factors

The link between social deprivation and drug use is well established. The review found that social factors also influenced treatment outcomes. Unemployment and housing problems had a ‘marked negative impact’ on treatment outcomes and increased the risk that someone would relapse after treatment.

Changes in treatment population

The review used modelling to estimate the likely size, characteristics, and needs of the treatment population over the next 4 years. Two changes in particular were expected to have implications for services and the measurement of their outcomes. First were changes in the profile of drugs for which treatment was being sought. Increases in the use of new psychoactive substances and prescription drugs were expected to continue. Second was the ageing profile of opiate users in treatment. Older heroin users (aged 40 and over) accounted for an increasing proportion of those in treatment, and the authors estimated that this proportion would continue to grow over the coming years. This cohort have entrenched dependence over a long period of time and their needs are complex. They experience cumulative physical and mental health conditions as well as being more susceptible to overdose. The reviewers argued that stakeholders should maintain a ‘realistic recovery ambition’ for this cohort, accepting that they were less likely to complete treatment than ‘newer’ users.

Indicators

The authors make a number of recommendations for the improvement of local and national drug treatment outcomes and their indicators. At the time of the review, the primary treatment outcome in England was the sustained successful completion of treatment. ‘Successful completion’ was defined as where a user had left treatment free of their dependence, was not in receipt of an opiate substitute, and did not re-present for treatment for 6 months. Based on the findings of the review, it was recommended that this period be extended to 12 months to ensure that post-treatment recovery support be maintained.

It was recommended that drug treatment indicators for opiate users be segmented into those for ‘new users’ and those for the older more chronic cohort of users. This would allow for the fact that it is much harder to effect change among long-term users who have very entrenched patterns of use and complex health and social needs, when compared to opiate users who engage with treatment after a shorter period of opiate use. It would allow for an increased focus on providing the older cohort with access to the primary and specialist healthcare services they might need.

More generally, the report concluded that drug treatment outcomes should be expanded to better reflect the breadth of the benefits of drug misuse interventions. In summary, they suggested developing a set of indicators around the following: waiting times for treatment; the proportion of opiate and crack users in treatment; illicit opiate use in treatment; drug-related deaths and drug-related hospital admissions; incidence of blood-borne viruses; offending behaviour; treatment entry rates following prison release; employment status; and housing status.

1    Public Health England is an executive agency of the Department of Health in England. It offers advice and support to their government, local authorities and the National Health Service, based on ‘world-class science, knowledge and intelligence, advocacy, partnerships and providing specialist public health services’. For more information on PHE, visit https://www.gov.uk/government/organisations/public-health-england/about

2    Burkinshaw P, Knight J, Anders P, Eastwood B, Musto V, White MJ and Marsden J (2017) An evidence review of the outcomes that can be expected of drug misuse treatment in England. London: Public Health England. https://www.drugsandalcohol.ie/26696/