BACKGROUND: Mortality cohort studies among people who are using drugs (PWUD) form an important piece of the puzzle to describe the drug situation and the individual and public health burden of drug use. We mapped recent cohort studies among PWUD in order to enhance comparability of results across Europe, to support the implementation of mortality cohort studies, and inform policy making. *** METHODS:
The study was conducted in 2020-21 in the 27 EU Member States, Norway and Turkey. The mapping exercise draws on contributions via questionnaires from national specialists and REITOX Focal Points from these countries, as well as on information provided in the standard annual reporting to the EMCDDA. *** RESULTS: 25 countries responded, of which 22 reported published and unpublished studies conducted within the last ten years. The mapping identified six running cohort studies and one large multisite study in the Czech Republic, Norway and Denmark. Four countries report concrete plans for new cohort studies. The studies reviewed were significantly heterogeneous in extent of follow-up, included populations, sample sizes, person-years (PY) and other variables. Crude mortality rates ranged from 2.3 per 1,000 PY (95% CI 1.2-4.4) in Spain to 28.8 per 1,000 PY (95% CI n.a.) in Latvia. Standard mortality ratios ranged from 3.4 (95% CI 3.3-3.5) in psychiatric patients in Poland to 39.4 (95% CI 0.2-220.8) in street-recruited female IDUs in Norway. Main causes of deaths included overdose, HIV/AIDS, other infections, cancer and cardiovascular disease. *** CONCLUSION: PWUD in Europe suffer a high excess risk of mortality compared to the general population. Monitoring of mortality among drug users requires regular updating of information and data on a European basis. The large variety of measures to investigate mortality risks calls for a more standardised reporting of mortality rates and ratios by specialists in those fields, if premature and preventable deaths are to be avoided.