Substance-related poisonings and homelessness in Canada: a descriptive analysis of hospitalization data

Canada is currently experiencing an overdose crisis affecting people from all walks of life. The Public Health Agency of Canada (PHAC), in collaboration with the provincial and territorial (PT) offices of Chief Coroners and Chief Medical Examiners, PT public health and health partners, and Emergency Medical Service data providers, releases quarterly surveillance data on apparent opioid and stimulant toxicity (overdose) deaths and Emergency Medical Services responses for suspected opioid-related poisonings (overdoses) ¹. PHAC also collaborates with Health Canada to report on hospitalizations for opioid- and stimulant-related poisonings (overdoses) using hospital administrative data from the Canadian Institute for Health Information (CIHI) ¹. In addition to ongoing surveillance, PHAC releases targeted analytical reports to help fill gaps identified by stakeholders on specific topics related to substance-related harms.

There are many factors that can play a role in substance use and related harms, including a person’s living situation. It is estimated that in Canada, there are on average at least 235,000 people experiencing homelessness in a given year and at minimum 35,000 on a given night ². Across the country, an additional 50,000 people a night could be experiencing hidden homelessness ². Hidden homelessness refers to people who are temporarily staying with friends, relatives or others because they have nowhere else to live and no immediate prospect of permanent housing ². The number of people experiencing homelessness in Canada remains very difficult to estimate, yet this number is thought to be increasing ^{2, 3}. The rates of substance use are disproportionally high among people experiencing homelessness compared to people with secure housing ^{4, 5, 6, 7, 8} and people experiencing homelessness are at a greater risk of substance-related harms ^{9, 10, 11}. Further, during the COVID-19 pandemic, some disparities in health have widened, particularly among some hard-to-reach populations, including an increase in the number of people experiencing homelessness, as well as an increase in the number of substance-related poisonings across the country ^{12, 13}.

It recently became mandatory to capture homelessness status upon admission to hospitals in the CIHI’s national hospitalization data effective 2018 ¹⁴. In response to this newly available data, the objective of this analysis is to describe patterns of substance-related poisoning hospitalizations in Canada (excluding Quebec) among people with housing and people experiencing homelessness using the CIHI’s Discharge Abstract Database. Data are presented for the time period from April 1, 2019, to March 31, 2020, and therefore most of the data included in this analysis capture the pre-pandemic period. This report examines patterns by patient demographics (sex and age), context of the poisoning (substances involved and intention of poisoning), hospitalization characteristics and outcomes (length of stay, intensive care unit admission and discharge disposition), and co-diagnosed mental health conditions. This analysis includes poisonings due to opioids, stimulants, cannabis, hallucinogens, alcohol, other depressants, and psychotropic drugs. To our knowledge, substance-related poisoning hospitalizations among people experiencing homelessness have not yet been reported publicly at a national level using this data source. The results of this analysis can be used to help better understand the intersection of homelessness, mental health, and substance-related harms and how hospital care is experienced differently by people experiencing homelessness.

Read the full report here.