The Substance Use and Health Intelligence Linked Dataset (SHIeLD) [1] is a national, population-based, retrospective, linked administrative open cohort of people with problematic drug use in Scotland, with an initial focus on those prescribed opioid agonist therapy (OAT). It is based on multiple administrative databases recording drug-related health harms, treatments, and other exposures held by Public Health Scotland (PHS). SHIeLD was established in 2019 to address three main public health policy and research aims:

• To estimate the size and composition of Scotland’s population of people dependent on opioids.

• To establish trends in morbidity, drug-related mortality, and other causes of death among people who use drugs.

• To assess the impact of OAT and other interventions on morbidity and mortality.