The treatment demand indicator (TDI) is an epidemiological indicator, used in the European Union (EU), with the aim of providing a common format on collection and reporting of data on people seeking treatment for problem drug use. A recent study reviewed the implementation of the TDI and the data analysis and trends it has provided.1

The TDI is one of five key epidemiological indicators of the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA). The TDI provides a common format that is used to collect specific information on the number, characteristics, and substance use patterns of drug users entering treatment in European countries. The information collected can provide data on general trends in problem drug use and treatment uptake and patterns. The information that is collected through the TDI is used to inform the yearly European Drug Report and the Statistical Bulletin. TDI data from Ireland are provided from the National Drug Treatment Reporting System to the EMCDDA, with the most recent data published in April 2019.2

Treatment data tends to be the primary source of information on the drug user population at national level, providing a substantial sample of the entire population with drug problems, making it a highly valuable data collection tool. Data are used to analyse the availability and accessibility of treatment services, providing important information for evaluation and planning of treatment services.

As the TDI collects standardised information, it enables analysis and comparisons to be made in treated problem drug use across European countries. The EMCDDA is responsible for the collection of data using the TDI and it coordinates this data collection through 30 national monitoring centres. In 2012, the TDI underwent a revision, whereby the current protocol used is TDI Protocol 3.0.3

This review looked at the information collected through the TDI over the last 10 years, and its implementation.

Key findings

Some of the most recent findings (for 2015 or the most recent year available) show that in 2015 some 29 EU countries reported data on 457,811 clients entering drug treatment from 6,846 drug treatment centres. Of these, 37% were first-time entrants to treatment; 80% of first-time treatment entrants were male, with a mean age of 33 years. Some 37% of the clients were unemployed (compared with 9.4% in the general population), 7% were homeless and/or without stable accommodation. In 2015, across Europe, opioids, mainly heroin, accounted for 38% of the clients, followed by cannabis at 31% and cocaine at 13%.

Trend analysis for the last 10 years has shown the changing pattern of drug use. Data for trend analysis in Europe are only available since 2006. In the period 2006–2015, the number of countries reporting TDI data rose from 27 to 29, and the number of clients increased from 396,349 to 467,811.

First-time treatment entrants between 2006 and 2015 reporting the primary drug problem as opioids decreased from 56,000 (37%) to 33,000 (21%). In most European countries, the number of first-time treatment entrants for primary cannabis use has consistently increased from about 43,000 (28% of all new drug clients) in 2006 to about 75,000 (47% of all new drug clients). Trend analysis is carried out for all reporting countries; however, significant differences to the general analysis can exist between individual countries. These country differences should be considered when reporting on European drug treatment demand data.

TDI data limitations

While the TDI provides important data and is a highly valuable tool, some of its data limitations should be considered. The TDI represents only a certain part of the drug treatment system, and this representation can vary significantly across the different countries. How data are collected can differ between countries and there can be fluctuations in data reporting due to the number and type of treatment centres reporting as well as the number of clients. Double counting also exists within the data, where individuals are registered more than once in the database, leading to an overestimation of the number of individuals in treatment. Another TDI limitation to consider is the restricted range of substances included in the data collection. Data are only collected on illicit drugs, no data on tobacco are collected, and information is only collected on alcohol if it is reported as a secondary drug for entering treatment.

However, the TDI is the largest drug-related dataset in Europe, and is extremely useful for policymakers at European level. The common data collection tool enables drug treatment professionals to compare their national treatment data against other countries to try to improve national responses. It is an extremely important source of information providing evidence on the extent and patterns of drug use and treatment service utilisation across Europe, Norway, and Turkey.

1    Montanari L, Pirona A, Guarita B, Hedrich D and Mounteney J (2019) The experience of the treatment demand indicator in Europe: a common monitoring tool across 30 countries. J Stud Alcohol Drugs, Suppl s18: 139–51. https://www.drugsandalcohol.ie/30226/

2    Health Research Board (2019) National Drug Treatment Reporting System 2011–2017 drug data. Dublin: Health Research Board. https://www.drugsandalcohol.ie/30197/ and www.hrb.ie/publications

3    European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) (2012) Treatment demand indicator (TDI) Standard protocol 3.0: guidelines for reporting data on people entering drug treatment in European countries. Luxembourg: Publications Office of the European Union. https://www.drugsandalcohol.ie/18436/