BACKGROUND: A number of studies show that an intensification of the policing of illicit drug markets has an impact on public health. The impacts are largely seen as negative.
AIMS: The aim of this paper is to describe the basic characteristics of data collection and to review the aspects related to data collection and its context that might influence the law enforcement indicators (drug law offences and offenders). METHODS: This work is based on research on the literature and grey zone materials, which consisted of reviewing reports published by relevant institutions and by searching in specialized databases.
RESULTS: Long-term indicators based on police statistics available for the Czech Republic come from the Crime Statistics System (ESSK) and from data collected by the National Drug Headquarters (NPC). The difference between the ESSK and NPC data lies in the reporting procedures and their changes and specificity as regards the substances involved in drug law offences.
The review identified different aspects of data collection and its context that have the potential to influence the indicators. Nine events with such potential were identified in three areas: legislation, the reporting system, and the structure and priorities.
The events that have the greatest potential to influence the time series are related to the reporting system, structure, and priorities. CONCLUSIONS: The review may assist and facilitate informed analysis and interpretation of drug-related law enforcement indicators individually or in combination with other indicators, using time series analysis as well as comparative approaches.