## Overview of the data

Tables and graphics present summary information on the estimated numbers of problem drug users and injecting drug users, along with the corresponding prevalence rates in the adult population (aged 15 to 64). Estimates are made by a variety of methods in each country. Data are presented for the most recent years available. Estimates at the national level are likely to show lower variability than sub-national estimates.

Time trend analysis is restricted by the fact that few countries are able to provide regular estimates of PDU prevalence and even fewer can provide regular estimates of IDU prevalence. This suggests the need for strengthening surveillance capacity is this area.

The full information on which the summaries of data presented in tables and graphs are based can be found in the supplementary downloadable tables (PDU-102, PDU-103 and PDU-105).

## Summary points

Table PDU-1 gives a summary overview by country of the latest available national level estimates of problem drug use. Problem drug use (PDU) estimates are given in part (i) and injecting drug use (IDU) estimates and problem opioids use (POU) estimates in parts (ii) and (iii), respectively. In general, estimates should not be compared across countries without assuming or inferring that study methods, data sources and definitions used, etc. are sufficiently comparable.

Table PDU-102 gives full information on national level estimates available at the EMCDDA, including historical data. Part (i) lists the PDU estimates (including the available estimates of subgroups like e.g. males, females, problem amphetamine users, etc.) and part (ii) the IDU estimates.

Table PDU-103 gives full information on sub-national level estimates (local, regional) available at the EMCDDA, including historical data. Part (i) lists the PDU estimates and available estimates of subgroups and part (ii) the IDU estimates.

Figure PDU-1 and Figure PDU-2 show the latest available national estimates of problem drug use. All problem drug use is shown in Figure PDU-1, part (i), problem opioid use in Figure PDU-1 part (ii), and injecting drug use in Figure PDU-2.

Table PDU-104 shows trends in current injecting among all clients asking for drug treatment with heroin as their primary drug. For more information on the treatment demand data, please consult the Treatment demand indicator.

Table PDU-105 gives background information for Figure PDU-3 on infectious diseases studies among IDUs, from which data on the proportions of young and new injectors in the samples was obtained. Figure PDU-3 shows proportions of young injectors (aged less than 25) and proportions of new injectors (injecting less than two years) in samples of IDUs tested for infectious diseases. For more information on these studies and for the corresponding infectious diseases data, see the Drug-related infectious diseases indicator.

Table PDU-6 shows time trends in national estimates of PDU for countries where sufficiently comparable data for several years were available for overall problem drug use in part (i), for problem opioids use in part (ii), for injecting drug use in part (iii) and for problem stimulant use in part (iv).

Table PDU-0 lists bibliographic references.