New indicators to compare and evaluate harmful drug use among adolescents in 38 european countries

AIMS -New trends in drug consumption reveal increasing polydrug use. Epidemiological indicators in the current use are based on the prevalence and the associated potential harm of a single "main" substance. We propose new indicators to evaluate frequency and potential harm of poly-drug use. The indicators are used to compare drug use among countries based on survey data on adolescents' substance use in 38 European countries. METHODS -The approach is based on analysis of the frequency of use in the various population samples: lifetime use, twelve months use or last thirty days, depending on available data, and on the risk of harm for the substances used. Two indicators are provided: the frequency of use score (FUS) by summing the frequency of use of each substance, and the polydrug use score (PDS) that weight all the substances used by their risk. RESULTS -The indicators FUS and PDS were calculated and the distribution functions were used to characterise substance use across ESPAD countries. The analysis shows important differences in poly-substance use severity among countries presenting similar prevention policies. CONCLUSIONS -Systematic analysis of substance use and the related risk are of paramount interest. The proposed indicators are designed to better monitor and understand consequences of polydrug use and to measure the resulting risk at country or population level. The indicators may also be used to assess the effects of policy interventions.