Methods and definitions

Information on the number of people seeking treatment for a drug problem provides insight into general trends in problem drug use and also offers a perspective on the organisation and uptake of treatment facilities. Treatment demand data come from each country with varying degrees of national coverage, principally from outpatient clinics' treatment records.

The objective of the TDI project is to extend the detailed data collection to a full coverage on all the treatment centres in order to have a better picture of the European clients demanding treatment for their drug use. The collection system classifies clients by primary and secondary drugs used: primary drug is the drug reported as the drug that causes the client the most problems. It can be based on problems as defined by clients or on short diagnoses based on the ICD-10. The main drug is also the main reason for asking for treatment; the secondary drugs are the drugs taken in addition to the primary drug; up to 4 different drugs can be recorded for every client.

Data are collected in two forms: summary data on all types of treatment centres (Sources: Standard Table 03 and Standard Table 04 – see below) and detailed data by centre type (outpatient treatment centres, inpatient treatment centres, low threshold agencies, general practitioners, treatment units in prison, and any other types of centres) (Sources: TDI detailed data collection by centre type – see below).

The treatment demand indicator measures the yearly uptake of treatment facilities by the overall numbers entering treatment for drug use and by the numbers among these of people entering for the first time (treatment incidence). Currently no data are collected on clients continuing a treatment from the year(s) before the reporting year; but a pilot project has started in 2005 with a group of 10 countries, in order to collect data on clients in continuous treatments

The EU Member States, the candidate countries and Norway collect the data on people starting a treatment for their drug use according to an established European protocol (theTDI protocol): the Joint Pompidou Group-EMCDDA Treatment Demand Indicator Protocol version 2.0, along with a more detailed Technical Annex. This protocol is the result of the developmental work undertaken by the Pompidou Group, the study of the national experiences, in particular in Germany, The Netherlands, Spain and United Kingdom and specific projects run by the EMCDDA.

The EMCDDA’s treatment demand indicator (TDI) provides a uniform structure for reporting on the number and the characteristics of clients referred to drug treatment facilities. The TDI Protocol is based on 20 items concerning the type of treatment provided and the characteristics of clients: socio-demographic data and drugs information.

The item list of 20 variables which should be collected by EU countries is reported below. For further details see the TDI Protocol at the web page ( The protocol provides a classification of treatment centres, defines which clients they should notify, and gives guidelines on methods of data collection, analysis and reporting.

There are some limitations related to the differences in data collection and reporting methods by each Member State. The number of missing cases for each data item is another limitation.

The results presented in the tables reflect that treatment information is not available from all the Member States. Differences in coverage among Member States affect data comparability. Some countries lack information on treatment units and the definitions used are not always 100 % compatible with the TDI protocol. Most countries have different kinds of treatment facilities and, moreover, the differences in the availability and use of drug treatment services could bias the results. The network of drug treatment centers has changed in the last decade; for example, methadone programs have expanded. These changes in treatment services could have influenced treatment figures over time. A last problem concerns the network of treatment centers and whether it is extensive enough to meet all treatment demands.

The quantity and type of treatment services offered provide important background information, but it is essential that treatment-related data be interpreted in the context in which they are collected.

For more information on data quality and data collection concerning the years 2000 to 2001 is published at the web page at the following address: Quality assessment of TDI data 2000-2001.

Specific analyses based on treatment demand data are also reported in the web page, detailing client profiles.