Statistical Bulletin 2023 — drug checking data, methods and definitions

This page provides methods and definitions information for drug checking data, which form part of the EMCDDA's Statistical Bulletin 2023.

Notes for interpreting the data

Data presented in the ‘Summary’ table section are from the users’ perspective and reflect what
consumers expect the drug to contain. These drugs were ‘acquired as’, for example cocaine
and submitted for testing as such (e.g. as cocaine). The distribution of drugs by drug checking service provides an indication of the drug markets and drug preferences within particular target populations, settings of use and geographical areas. It may also indicate quality concerns regarding specific drugs among consumers.
Data presented in the ‘Main results’ and ‘Substances identified’ tables reflect the actual content of the drug samples after chemical analyses performed by the drug checking services in each city. 

Purity data reported in the ‘Main results’ tables by drug provides information on how much of the expected substance is actually present in a drug sample. Purity data do not provide any indication of the content of the drug other than the expected drug, it is therefore not a good indicator of quality by itself. For example, a drug may have a high purity, while in addition to the drug it contains small amounts of unexpected and potentially fatal adulterants (additional psychoactive substances). Alternatively, a drug may have a low purity and in addition to the expected drug, it contains only excipients (non psychoactive cutting agents like milk powder). 

Adulteration data in the ‘Main results’ tables by drug data indicate the proportion of samples tested that contained only the expected substance (e.g. cocaine) or did not contain the expected substance (e.g. no cocaine detected), or contained the expected substance with one or more adulterants (unexpected psychoactive substances). The expected substance is the drug that the consumer acquired and expects to be present. Note that non-adulterated drug samples (‘contained only the expected substance’) will nearly always contain an unknown amount of excipients or filling agents (non-psychoactive substances like milk powder).

Data in the ‘Substances identified’ tables by drug indicates the number of samples by main drug tested (as acquired by the user) and the number and frequency of substances identified in these drug samples. Note that the percentage of substances identified by main drug category may be more than 100% as more than one substance may be detected in a sample.

Drug checking data provides information on the availability, purity and content of drugs submitted for testing by users of drug checking services. These data are also proxy indicators of current markets from the users’ perspective; drug use and trends, including NPS, especially among recreational users; potential drug-related risks for drug users.

The target groups attending drug checking services are primarily recreational drug users among the general public and party goers. Depending on the settings, high risk drug users are also using drug checking services. Drug checking settings include: Drop in (fixed drug checking office); music events (festivals - clubs); temporary city points; drug consumption rooms. 

All traditional drugs and a comprehensive list of new drugs are tested, always depending on the technological capacity of the respective drug checking services. Data from this network play an important role in informing national and EMCDDA Early Warning Systems and complement established epidemiological drugs monitoring instruments. 

Advantages

  • Analytical testing/confirmation - unlike many other datasets, these data are not self-reported but chemically analysed; 
  • “End of the chain” - drug checking data provides information about the content and purity of drugs at user level.
  • Timeliness - data available to the EMCDDA within 6 months.
  • Data coverage: Most existing services in Europe participate in the data collection and further steps involve expanding its coverage.
  • Only user submitted samples - Police seizures at events are not included. 

Limitations

These results measure the content of drugs submitted to drug checking services across Europe. They represent drugs used by a population willing to submit their drug for checking and with the opportunity of doing so. Conclusions drawn from these results to a wider population of people using drugs should be made with caution and are generally only indicative. Not all services use advanced technology - only services with such technology can provide adulteration and purity data. The location of acquisition and consumption may differ from the testing location. Therefore, drug checking data should be complemented with other national epidemiological data. Trends in some drugs tested can be influenced by big music events.

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