High and Repeated Hospital and Emergency Department Use for Mental Health and Substance Use in Canada.

Individuals with mental health and substance use (MHSU) conditions account for a disproportionate share of hospital and emergency department (ED) service use in Canada. This analysis draws on three Canadian Institute for Health Information indicators: 30-day readmissions, repeat hospitalizations and frequent ED visits for help with MHSU. Results show that rates across all indicators remained persistently elevated and, in 2024-2025, were approximately 8-9% higher than those in pre-pandemic baseline years. Higher rates are consistently observed among individuals living in lower-income neighbourhoods, adults aged 25-44 years and those with substance use-related conditions. Taken together, these indicator results point to recurring patterns of acute care use that reflect gaps in continuity, access to community-based care and integration across services. Strengthening transitions of care, expanding community-based supports and improving integration for individuals with complex and co-occurring conditions are critical to reducing avoidable acute care use.