The aim of this comparative study was to clarify indicators of drug misuse used in the different cities, to describe more clearly the extent of the problem taking into account differing cultural and policy contexts, and to Improve understanding and interpretation of such data within the Pompidou Group.

The epidemiology experts agreed that an approach based on cities was more feasible at this time than one comprising whole countries. At national level the situation is much more complex and can less readily be interpreted.
The study employed the following design:
1. review and summary of the data which are available on drug misuse in the seven cities;
2. critical examination of the degree to which commonly used indicators, such as drug-related deaths or police arrests, are consistent and comparable between cities;
3. assessment of the benefits and drawbacks of using these indicators to measure and interpret the extent and changing patterns of drug misuse;
4. comparison of trends and prevalence between cities, to the extent that this is found feasible from the previous stages;
5. consideration of what recommendations could be made in order to Improve comparability or elaboration of the indicators,
The results of this study, completed in autumn 1986, are described in 2 sections.