Evidence spotlight: drug safety testing

Rob Calder and Natalie Davies review the literature to see what can be learned...
Created On: 23 July 2021   (Last updated: 23 July 2021)

Rob Calder and Natalie Davies review the literature to see what can be learned about the effectiveness of drug safety testing and what circumstances are necessary for it to reach its full potential. They find that the answer to whether the intervention works depends on what the desired result is, which can vary by country and policy context.

Below we discuss some of the key issues around drug safety testing – featuring both a short read, which covers frequently asked questions, and a long read, which analyses four key studies (Measham, 2019; Olsen, 2019; Guirguis, 2020; Measham, 2020).

The short read

What is drug safety testing? Illicit drugs don’t come with a list of ingredients or detailed information about strength and dosage. Drug safety testing can fill in some of these gaps in the name of harm reduction – using forensic analysis to better understand what the drugs contain, how strong they are, and whether there are any unexpected ingredients.

What does it involve? Drug safety testing typically involves someone submitting a sample of their drugs for testing, and then receiving information about what the drugs contain, and how they can reduce their risk of harm should they want to go ahead taking the drugs.

Why does it matter? In 2019, there was a record number of drug-related deaths, predominantly from opioids but also from MDMA, cocaine and new psychoactive substances. Accidental overdoses are often caused by people taking a drug that is stronger than expected or contains an unexpected substance – something that drug safety testing has the potential to prevent.

What are the concerns? The main concern with drug safety testing is that people will be more inclined to take illicit drugs after hearing ‘reassuring’ feedback from a drug safety testing service, although it should be noted that this has not been validated by the evidence. Most (if not all) drug safety testing interventions involve staff highlighting that they ‘do not condone illicit drug use’ and that ‘illicit drug use always comes with some risk of harm’. The perception of drug safety testing interventions ‘greenlighting’ drugs, therefore, is more likely to be a value judgement or fear about harm reduction interventions in general, than a specific criticism of drug safety testing.

Is it effective? The outcomes vary. At an individual level, some people choose to dispose of their drugs after hearing the results, some take a smaller dose than they had planned, and some warn friends about drugs that aren’t what they were sold to them as. Even though it may be difficult to demonstrate that drug safety testing has an impact on the ultimate outcome – reducing drug-related deaths – a pragmatic reading of the other outcomes suggests that drug safety testing can reduce harms for people who use drugs.

What are the research gaps? In an ideal world (ideal for researchers anyway), you would have two identical festivals – one with, and one without, drug safety testing. There are two problems here. Firstly, no two festivals are exactly the same, and secondly, to get enough statistical ‘power’, you would need a lot of festivals and a lot of duplicate festivals.


The long read

If drug safety testing is intended first and foremost to be a form of harm reduction, then there are several ways for it to reach its potential. These include: real-time communication of results to the wider public; delivering results within a harm reduction conversation; and using multiple forensic analysis methods to provide detailed information about the contents and purity of drugs.

It is important to note, however, that harm reduction may not be the main driver for drug safety testing – for example, when key stakeholders or gatekeepers prioritise other outcomes, such as gathering intelligence about the illicit drug market or promoting treatment for substance use problems, or when they do not fully endorse harm reduction as a policy. This distinction is important to bear in mind when considering what drug safety testing is (spoiler alert: ‘it depends’), what outcomes we can expect (‘it depends’), and whether the intervention can be justified on the grounds of the evidence base (you get the picture, ‘it depends’).

Whether service users go on to dispose of their substances, take smaller doses, or continue as planned, the point of drug safety testing when delivered as a harm reduction intervention is to enable people to make decisions about their drug use based on known harms rather than hypothetical harms.

What is drug safety testing?

Drug safety testing, pill testing, street drug analysis, and drug checking are part of a group of interventions that involve testing illicit substances to determine what they contain (and in some cases, the amount and strength), and then communicating the results of those tests to people who intend to use the drugs and/or other stakeholders.

One of the concerns about drug safety testing is that it might give a ‘green light’ to using drugs, when this type of intervention can only ever provide partial information about the potential consequences of drug use. It may well be that drug safety testing cannot tell someone everything about a substance or how they will react to it; however, not all drug safety testing interventions were created equal; some provide a lot more information than others, and some lead to more harm reduction than others.

In the UK, drug safety testing has been delivered in festival and community settings by non-profit organisation, The Loop, with the agreement of local law enforcement. The term ‘drug safety testing’ was preferred by stakeholders as it emphasised that the aim was to help keep the public safe. The term also helped to distinguish it from testing for surveillance purposes such as in prisons or workplaces (‘drug testing’). At least two studies of drug safety testing have found that mis-selling drugs is common, highlighting the need for this type of intervention (1 2). This evidence has also shown that positive behavioural outcomes can follow drug safety testing: some people dispose of drugs after receipt of the intervention, particularly when they were mis-sold drugs.

In this context, it is important to note that the word ‘safety’ in ‘drug safety testing’ is not intended to convey absolute safety. Rather, drug safety testing aims to address some of the potential harms from drug use, by giving service users the opportunity to reduce risks that would have previously been hypothetical or unknown.

‘Drug checking’ has been piloted in the UK in a substance use treatment service in North Somerset (see our interview with Dr. Amira Guirguis). This service was notable for being the UK’s first Home Office-licensed intervention of this kind. In this case, the term ‘drug checking’ was chosen to emphasise the comparatively simple (as opposed to detailed) forensic analysis that the intervention offered, and to avoid any assumptions or inferences about the ‘safety’ of drugs.

The intervention involved screening a relatively small sample of drugs and focused on using this to provide a route into treatment for substance use problems. The primary aims were: (1) to check for particularly dangerous substances (e.g. fentanyl); and (2) to get people through the door to use the service as the stepping stone to other substance use (or related) treatment services.

What outcomes can we expect?

The outcomes of drug safety testing can vary from intervention to intervention, but potentially extend from the individual level (e.g. people choosing to dispose of their drugs after hearing the results), to the community level (e.g. fewer adverse events relating to a dangerous substance on the market), and societal level (e.g. reduction in population overdose rates and drug-related deaths). The case for, or against, drug safety testing depends on the qualities of the specific intervention being proposed, and whether there is evidence of effectiveness or unintended harms associated with these qualities.

In 2016, a drug safety testing service was piloted on the grounds of a festival in England. A researcher involved with the project reported that a fifth (20%) of substances that were analysed differed in content from how they had been advertised or sold. When the same researcher trialled drug safety testing at a drugs service, community centre and church, the findings were similar – 24% of samples submitted for testing were not what the service users had expected. Some participants in those studies had no idea what the contents of the drugs were before testing and were potentially going to take them anyway. While the threshold for overdose varies across different substances, taking an unknown substance puts a person at an incredibly high risk of overdose and other drug-related harms.

These drug safety testing services used several different methods of analysis; three methods in the festival study, and six methods in the community study. In both cases, the thorough analysis meant that drug testing staff could provide detailed information about the content and purity of substances and could provide this information with a high degree of certainty because the results could be triangulated.

At services delivered by The Loop, many service users indicated that they were taking steps to reduce the harm associated with their illicit drugs:

  • Two thirds (67%) of people at the festival who found out that their drugs were not what they thought they were handed over the rest of those drugs for disposal. By contrast, one in ten (9%) people whose drugs were as expected disposed of their drugs. Some people said that they would take the substance over a longer time period or after leaving the festival, and others said that they intended to take a smaller quantity of the drug.
  • In the community settings, nearly half of people (49%) said they would take the same dose as intended before the consultation. This usually happened in cases where the test result, strength and accompanying advice on purity trends and dosage were all ‘as expected’. Over a third (35%) said that they would be more careful about mixing that drug with other substances; 28% said they would take a smaller dose in the future, suggesting that the drugs were either stronger than expected, and/or those people had developed a greater appreciation of the risks of taking their usual dose. One in ten people disposed of their drugs or said they would dispose of their drugs. Over a third (38%) of service users said they would alert their friends and acquaintances about substances of concern and 9% said they would alert their dealer, suggesting that testing could provide a useful feedback loop to wider communities of people who use drugs and to suppliers not aware of exactly what they are selling.

The year that the UK festival drug testing service was introduced, the festival reported a 95% reduction in drug-related hospital admissions from 19 in 2015 to one in 2016. Stakeholders suggested a number of possible explanations for this fall. These included a heightened awareness of contaminants in circulation among festival goers as well as early presentation for drug-related problems and a greater confidence amongst paramedics in treating drug-related presentations onsite. This evidence, along with indications of behavioural change (such as disposing of drugs or taking smaller quantities), provided support for this particular drug safety testing intervention as a way of reducing harm among people who take drugs.

The testing service also reported interesting data about the difference between drugs sold onsite and those that festival goers brought with them. Overall, 20% of drugs tested by the service were not what they had been sold as; however, mis-selling was twice as high among drugs bought at the festival compared with those bought offsite (27% vs. 12%). This information was shared among all onsite agencies at the festival (including police, welfare, security and paramedic services) and targeted alerts were then circulated for chloroquine and ketamine that was being mis-sold as cocaine, as well as for pills with high MDMA content. This raised some important questions about the best ways of reducing harm from taking drugs at festivals. The high levels of mis-selling onsite indicate that security measures such as searching festival goers for drugs on entry may be counterproductive if they encourage more onsite purchases.

A festival-based, pill-testing intervention in Australia, meanwhile, was successfully rolled out and valued by festival goers and other stakeholders, but the relatively narrow scope of the service meant that there were missed opportunities for harm reduction.

Towards the end of April 2019, several media outlets were reporting that the service at the Groovin the Moo festival had potentially saved seven lives (1 2 3) – referring to seven festival goers who had been mis-sold N-ethyl pentylone, and who subsequently disposed of their drugs. However, this testing service had an agreement with the Australian Capital Territory Government that they would not share information about potentially dangerous substances with other festival patrons, and therefore it is likely that other people in possession of N-ethyl pentylone would have remained unaware of this and therefore remained at risk.

In contrast, when similar batches of mis-sold drugs have been detected at UK festivals, alerts have been posted to social media with photographs and details of the contents, and shared by the social media accounts of festival management, police and other onsite agencies.

The service at the Groovin the Moo festival was also unable to assess the purity or strength of substances. Yet, some patrons, staff, and other stakeholders believed that it could. The independent evaluation of the service somewhat added to the confusion. It outlined the pros and cons of two options for forensic analysis in drug testing services, but described only one – which could not test for purity – as being realistic for onsite testing at festivals. This created the impression that, within current resource and technology constraints, testing for purity at festivals was not possible.

An inquest into the death of six patrons of music festivals in New South Wales heard extensive evidence about the range and efficacy of testing methods currently available. With the input of Dr. David Caldicott, emergency medicine specialist who also works for Pill Testing Australia, the inquest heard that there is a common misunderstanding that drug safety checking services cannot test for purity:

“One of the oft repeated criticisms of drug checking at music festivals is that purity cannot be tested for. Clearly this is incorrect. There are methods for testing for purity. Usually this is done in a fixed laboratory setting using a form of spectrometry. However, the court heard that there has been testing for purity in a music festival setting in parts of Europe for many years. It requires some commitment to set up, as expensive equipment must be transported carefully and efficiently.”

This point was significant because it highlighted that services differ in their capacity to make known the content of illicit drugs, and illustrated that a limitation of one particular service or method can be (incorrectly) used to criticise drug safety testing in general.

Does evidence of effectiveness outweigh the risks (or fears)?

The first research paper detailing findings from the UK Home Office-approved testing site included relatively little about harm reduction outcomes and implications, although more information is expected to follow about improving detection quality in future interventions of this kind. The paper did, however, report that pharmacist-led drug checking in a substance misuse service was feasible and that there appeared to be no adverse consequences that could compromise Home Office support. The authors said:

“…there were no incidents of violence or aggression whilst the service was in operation.”

It was interesting for the study to note the absence of such behaviour, particularly as no evidence was cited about this being a risk or unintended consequence. The inclusion of this outcome may have reflected a desire to confront negative perceptions, or been out of an abundance of caution as the first service to operate under a Home Office licence.

This hints at one of the important issues with drug safety testing. For some people, drug safety testing may conjure a very strong image of behaviours believed to be associated with illicit drug use. For example, they may imagine long queues of ‘violent drug users’ hanging around waiting to get their drugs tested. They may expect an increase in public disorder and crime in surrounding local areas by these services attracting people who use drugs and dealers from elsewhere – known as the ‘honeypot effect’. This has certainly been a perception about drug consumption rooms – but as with drug safety testing, the feared adverse effects have not (yet) materialised in the literature. However, addressing these concerns (regardless of their origin or bias) can be as relevant to implementation as whether those initiatives work or not.

Whether service users go on to dispose of their substances, take smaller doses, or continue as planned, the point of drug safety testing when delivered as a harm reduction intervention is to enable people to make decisions about their drug use based on known harms rather than hypothetical harms. In other words, it is not to discount the harms of illicit drug use, but to try to minimise harm by taking away some of the unknowns. The experiences in drug safety testing services demonstrate how quickly such a simple idea can become complicated. They also demonstrate the high levels of concern that open conversations about drugs can still bring about.

by Rob Calder and Natalie Davies

Informed by analyses by Drug and Alcohol Findings on the UK’s first onsite drug safety testing service and a pill-testing service trialled at an Australian music festival.

The original articles can be found here:

Drug safety testing, disposals and dealing in an English field: Exploring the operational and behavioural outcomes of the UK’s first onsite ‘drug checking’ service. By Fiona Measham. Published in the International Journal of Drug Policy (2019).

ACT pill testing trial 2019: program evaluation. By Anna Olsen and colleagues. Published by the Australian National University (2019).

Piloting the UK’s first Home-Office-licensed pharmacist-led drug checking service at a community substance misuse service. By Amira Guirguis and colleagues. Published in Behavioral Sciences (2020).

City checking: Piloting the UK’s first community-based drug safety testing (drug checking) service in 2 city centres. By Fiona Measham. Published in the British Journal of Clinical Pharmacology (2020).

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