Blood-based biomarkers for early diagnosis of Alzheimer's disease: a current systematic review of diagnostic accuracy studies.

The opioid crisis is a major public health issue globally, especially in Canada, the United States and Europe [–]. Between 2019 and 2021, the annual number of opioid-toxicity deaths in Canada more than doubled, comprising more than 25% of deaths among young Canadians []. The opioid overdose crisis in Canada has resulted in a substantial increase in deaths, hospital admissions, and blood-borne infections associated with substance use [, ]. While fatal overdoses have sharply risen nationwide, Western Canada has been predominantly impacted by this epidemic []. In particular, Saskatchewan has reported a nearly 300% increase in opioid-toxicity deaths between 2010 and 2020 []. The rise in overdose rates in Saskatchewan has been further accelerated by reduced access to harm reduction services and an increasingly unstable, illicit drug market []. The high rates of opioid-related harms, including illness, hospitalization, and death, underscore the urgent need for expanded access to healthcare, social services, and harm reduction programs. The risks associated with opioid use are particularly acute for people who use drugs (PWUD), especially people who inject drugs. Research suggests that approximately one-in-five people who inject drugs is at risk of a non-fatal overdose each year []. The factors that mediate risk of overdose are complex and multifaceted, encompassing social, biological, political, and environmental dimensions. Structural vulnerabilities, such as poverty, housing instability, punitive policies (e.g., criminalization of drug use, restriction on harm reduction programs), and historical oppression, limit a person’s ability to engage in risk-reduction practices (e.g., needle exchange) and access interventions (e.g., substance use treatment) []. Additionally, people who experience incarceration, homelessness, and sex work are disproportionately affected by poorer physical and psychological health outcomes []. In many cases, substance use becomes a coping mechanism for these challenging conditions, furthering the increased risk of overdose []. Indigenous Peoples in Canada are disproportionately affected by opioid related harms, including overdose mortality and HIV/STBBI transmission, due to intersecting structural inequities rooted in colonialism, systemic racism, intergenerational trauma, and ongoing barriers to healthcare access [, , ]. In Saskatchewan, these inequities are particularly pronounced, with Indigenous communities experiencing higher rates of drug toxicity deaths and related health outcomes compared to non-Indigenous populations []. Regina is a mid-sized prairie city with spatially concentrated social and health inequities, including disproportionate impacts of poverty, housing instability, and drug-related harms []. As of September 2025, there are seven urban Indigenous reserves in Regina []. Urban reserves in Saskatchewan influence patterns of service access, community engagement, and the demographic composition of populations reached through harm reduction interventions [].