Evidence for action globally

We heard in Step 1.16 how the World Health Organization and other international agencies recommend a comprehensive and evidence-based approach to tackling the adverse public health effects of drug use. We also heard in Steps 1.14 and 1.15 how social contexts and policy environments can affect the capacity of individuals and communities to reduce risk. In this Step, we introduce some additional materials as evidence in support of harm reduction globally.

Do No Harm

In 2016, the United Nations Joint Programme on AIDS (UNAIDS) released a report called “Do No Harm”. The principle of ‘do no harm’ is, of course, embraced in the Hippocratic Oath which underpins the ethics of medicine. The UNAIDS report focuses specifically on ‘health, human rights and people who use drugs’. The report is an extremely useful one to read alongside this course. We will come back to elements of this report again in Step 2.8, but here, we suggest you read pages 2-6 (Introduction) of the report.

What are the highlights of this Introduction for you? Taken together with what you have heard from Annette Verster, of WHO, in Step 1.16, what do you consider to be the key lessons when designing-up a package of harm reduction interventions?

First, the report draws attention to the “vast majority of the 246 million people who use drugs” having “been criminalised by national legislation and marginalised by society” (UNAIDS, 2016: 3). It links practices of criminalisation with increased risk of harm, saying that people who use drugs have been “often denied the means to protect themselves from HIV, hepatitis C virus, tuberculosis and other infectious diseases”.

Second, the report emphasises that the tools and strategies required to improve the health and lives of people who use drugs “are well known and readily available” (UNAIDS, 2016: 3).

This is what the report says

Needle-syringe programmes reduce the spread of HIV and other blood-borne viruses. Opioid substitution therapy and other evidence-informed forms of drug dependence treatment curb drug use, reduce vulnerability to infectious diseases and improve uptake of health and social services.

Naloxone is an effective treatment for opioid drug overdoses and saves lives. Treatments for HIV, hepatitis C virus and tuberculosis greatly reduce morbidity and mortality. The United Nations Office on Drugs and Crime and the World Health Organization and UNAIDS recommend using these services within a comprehensive package of health interventions.

The report leads to making five policy recommendations and ten operational recommendations. These are available to read here. As you move through the course, you will see how these policy and operational recommendations have relevance to different aspects of harm reduction. The UNAIDS report summarises the body of evidence in support of these recommendations.

Evidencing impact

Two cornerstone interventions in the package of interventions that make-up harm reduction are needle and syringe programmes (NSP) and opioid substitution therapy (OST). Let us consider these two interventions in more detail. We would like to draw your attention to some key articles which have shaped the ‘evidence-base’ to date. Don’t worry if the following part is a bit too academic or if you are unfamiliar with some of the technical language. The articles we recommend here is not an essential part of learning for this course, but is made available for those who are particularly interested in the body of research evidence linked to harm reduction.

For learners who want to read a key article about evidence in support of opioid substitution therapy (OST), we suggest the following published paper, available here (You can also download a copy at the bottom of this page)

The above paper is a ‘systematic review’ and ‘meta-analysis’ of ‘prospective’ observational studies with a focus on assessing the impact of OST on HIV incidence among people who inject drugs. A meta-analysis means that the results of different comparable studies are combined. The focus on prospective studies means that the review is focusing on the highest quality evidence of impact available, that is, from randomised controlled trials, prospective cohort studies and case-control studies.

What is the take-home message of this article? For us it is this: “Opiate substitution treatment was associated with a 54% reduction in risk of HIV infection among people who inject drugs”.

The most commonly prescribed forms of OST are the opioid agonist treatments methadone maintenance therapy and the partial agonist buprenorphine maintenance treatment, or increasingly popular Subuxone (buprenorphine plus the antagonist naloxone). OST is usually taken orally and therefore reduces the frequency of injection and unsafe injecting practices. In addition to reducing HIV risk, OST has also been shown to increase health and social functioning, decrease crime, and reduce the frequency of injection and unsafe injecting practices. Evidence suggests that OST is most effective when it is continuous and provided at adequate doses.

For learners who want to read some key articles about evidence in support of needle and syringe programmes (NSP), we suggest the following two published papers, by Aspinall et al (2014) available here, and by Platt et al (2016) available here (You can also download a copy at the bottom of this page)

There is a wealth of evidence in support of NSP. But one thing we can notice in comparison with the systematic review of evidence in support of OST, is that there are no randomised controlled trials of NSP. This is because it is difficult (for instance, almost impossible to prevent people from using a pharmacy of NSP) as well as unethical (the intervention cannot be withheld from people whose health depends on it).

Both of the above studies focus on the reduction of blood-borne transmission risk (HIV and hepatitis C virus) as the outcome of interest. What can we take from these two studies?

In the Aspinall et al (2014) review, which undertook a meta-analysis of pooled data across reviewed studies, NSPs are 48% reduction in HIV transmission. The higher quality studies in the review showed stronger evidence of reduced transmission linked to regular contact with NSPs.

In the Platt et al (2016) review, where the focus is reduced hepatitis C infection rather than HIV, high coverage NSP gives a 23% reduction in hepatitis C transmission. This review finds a great deal of heterogeneity, or variation, between the studies reviewed. In Europe, which yields a more consistent measure of NSP exposure, NSPs reduce HCV transmission by 50% or more.

The Platt et al (2016) review also gives evidence on OST, finding that OST gives 50% reduction in HCV transmission. This work points to OST impact being potentially different according to gender, which corroborates other evidence that women are at increased risk of acquiring hepatitis C compared to men and may have poorer access to OST.

If you look at these studies closely, what concerns might you have about the evidence they produce? Some concerns might include:

• There are few studies included from lower income and non-Western settings.
• Studies tend to focus on blood-borne risks when there are other health benefits of OST and NSP.
• Systematic reviews tend to grade evidence ‘low’ or ‘weak’ when randomised controlled trial evidence is not available, and yet for many interventions, such as NSP, this is not feasible nor ethical, and neither is it necessary before interventions should happen.
• Studies use different measures of intervention intensity, dose and coverage, and may therefore not always be comparable.
• It is difficult to disentangle the effects of single interventions, like NSP or OST, from other interventions and contextual changes in the environment.
• The impact of harm reduction is enhanced when interventions work ‘in combination’ rather than alone.
• Qualitative studies might tell us more about how harm reduction interventions are implemented in practice and how they are received by people who use drugs.

Additional reading

For a detailed assessment of the evidence of public health approaches in international drug policy, we also draw attention to a Lancet Commission on this topic, published in the Lancet in 2016 (Csete et al., 2016: 1427-1480), with a link here.

Harm Reduction works!

We hope this brief overview on research and evidence was helpful to gain better understanding of what is meant when Harm Reduction is presented as an ‘evidence based’ intervention.

There is of course much more research available. Feel free to explore the vast evidence-base yourself. But again, don’t worry if some of this was too technical. The bottom-line is that times and again, harm reduction is proven to reduce the transmission of infectious diseases, lethal overdose, and a range of medical and social harm.