Measuring the harms of substance use or poly-use in the nightlife scene: a pilot cross-country application

Drug use indicators that are capable of measuring the individual levels of harm following drug use, and, in particular, poly-drug use, have been proposed and applied to various drug user populations (Fabi et al. 2014; Mammone et al. 2014). Such indicators are based on individual drug frequency of use in a specific time period and expert rankings of harm related to various "classical" substances, proposed by van Amsterdam et al. (2010) and Nutt et al. (2010). These indicators allow the estimation of risk profiles for selected groups of individuals and comparisons, both over time and between populations. Recent advances regardng the ranking of drug use harms, proposed in a joint paper by van Amsterdam and Nutt in 2015, allowed a refinement of the indicators, separating the harm effects on self and on others following drug use. The application to the Italian ESPAD data and the study of the relationship between the values of the indicators and of the variables of status and those regarding the relationship with the parents of the analysed subjects showed a possible use of the indicators to plan targeted prevention interventions (Colasante et al. 2019).In the present study, we apply the same indicators to self-reported drug use in the nightlife Italian population related to a 12 months period, after having agreed with an interdisciplinary commitee, based in the Italian Early Warning System team, specifi pilot scores for the New Substances (NPS). Such substances appear, albeit in a very low proportion, among the substances used by the subjects participating in the Electronic Music Scene Survey.EMSS of the ALAMA project (https://www.eranid.eu/projects/alama-nightlife/) and have not been consiedered by Nutt and van Amsterdam in their work. Briefly, for each of the 16 harm criteria, used by van Amsterdam and Nutt in 2015, was identified the most harmful drug/drugclass, which was given the maximum score taking into account the consensus weights for both harm to users (cumulative weight of 53) and harms to others (cumulative weight of 47). Remaining drugs/drug classes were evaluated in relation to the most harmful drug. Harm scores given independently by the experts of the Italian EWS were discussed in order to obtain consensus on the final scores. On the basis of the complete set of scores for classical drugs and NPS the drug use indicators have been calculated. The correspondings distributions highlight different sub-populations (at least 41% consume more than just one illegal substance) and the correlation of the values of the indicators with state variables of the subjects are also studied providing useful results on variables for prevention. Data from the different countries of the ALAMA project will be compared in the near future when the complete ALAMA data set will be available for the application.