High levels of all-cause mortality among people who inject drugs from 2018 to 2022

Background: Mortality among people who inject drugs (PWID) is high, with overdose and HIV infection being the main causes of death. In Greece, there have been no data on mortality, and two HIV outbreaks have been recorded in this population in the past decade. In this study, we aim to estimate the all-cause crude mortality rate and the standardised mortality ratio in this population during 2018-2022. Methods: PWID recruited from two community-based programs in Athens and Thessaloniki during 2018-2021 were interviewed and tested for HIV/HCV. Data on vital status (deceased/alive) and date of death were obtained from death registries through December 31, 2022. All-cause crude mortality rates (CMR) and standardised mortality ratios (SMR) were estimated. Determinants of mortality were assessed using Cox proportional-hazards model. Results: Of 2,530 participants, 301 died over 8,543 person-years (PYs) of follow-up. The CMR (95 % CI) was 3.52 (3.15-3.94) deaths per 100 PYs; 3.10 per 100 PYs (2.68-3.58) in Athens and 4.48 per 100 PYs (3.74-5.37) in Thessaloniki. An increasing trend in CMR was identified over 2018-2022 in Athens (from 2.90 to 4.11 per 100 PYs, 41.5 % increase, p = 0.018). The pooled SMR (95 % CI) was 15.86 (14.17-17.76) for both cities and was particularly increased in younger individuals, females, those injecting daily, not enrolled to opioid agonist treatment and HIV -infected individuals. Older age, living in Thessaloniki, Greek origin, homelessness, history of injection in the past 12 months, and HIV infection were independently associated with higher risk of death. Conclusion: Mortality among PWID in the two largest cities (Athens and Thessaloniki) in Greece in 2018-2022 was high, with the population in Thessaloniki being particularly affected. The increasing trend in mortality in Athens may reflect the long-term impact of the COVID-19 pandemic. Preventive programs such as take-home naloxone, screening and treatment for HIV, are urgently needed.