The aim of the indicator is to assess the social-demographic characteristics (type of drug, gender, age, first use, education, employment, ethnic status) and the patterns of use (frequency of use, route of administration, duration, risk behaviours, polydrug use) regarding those being in treatment or out-of-treatment drug users who have the most serious social and health problems.
The ind/icators function is to estimate the number of the hidden drug users who are not involved in treatment and to measure the extent of the problem. In order to be able to operationalise the concept, according to the EMCDDA definition problem drug users are long-term and/or regular and/or injecting opiate, amphetamine, cocaine or polydrug users.
