Monitoring and assessing drug policies: scoring poly-drug use in the segments of the teenage population as a tool for cross country comparisons and economic evaluations. Preprint

Background. New trends in drug consumption show higher and higher proportions of poly-use. Epidemiological indicators used to monitor and evaluate drug policies are mostly based on the prevalence of users of the “main” substances (incidence would be the proper indicator) and the ranking of the harm of the substances is based on a single substance analysis (Nutt D. et al., 2007 and 2010, van Amsterdam J. et al., 2010). Methods. The following points are dealt with in the present contribution: - the segmentation of the consumer population; - the scoring of the harm of poly-use; - the application of the various indicators to respondents to various surveys; - the use of the prevalence of the teenage population as a proxy of incidence for cross country comparisons and a possible correction for estimating incidence; The segmentation is based on the frequency of use in the last 30 days declared by respondents of School Population Surveys. Poly-drug use is taken into account by adding up the mid frequency of the classes of the different substances used in the last 30 days. Scoring is based on van Amsterdam and others (2010). Principal component analysis is applied to reduce dimensionality. Results. Any user is characterized by the two scores: frequency of use and poly-use score. The two systems of scores allows for cross country comparisons. Prevalence and incidence of teenage population are estimated and used for monitoring and comparisons. Conclusions. The indicators based on the analysis of teenage drug users are very valuable due to the wide availability of reliable data on this populations coming from the School Population Surveys implemented with similar methodologies and questionnaires in several countries.