Increasing housing instability and changing spatial distribution of people who inject drugs in Montreal, Canada, 2011-2024.

Abstract

Housing instability contributes to poor health outcomes among people who inject drugs (PWID). Housing affordability in Montreal has declined since 2020. We described changes in the prevalence and spatial distribution of unstable housing among PWID. We analyzed data from the HEPatitis COhort (HEPCO) of PWID in Montreal across three time frames: 2011-2014, 2015-2019, and 2020-2024. Housing was categorized as stable, precariously housed, or unsheltered based on the Canadian Observatory on Homelessness definition. Postal codes of primary residence over the past month were geocoded using the ggmap package in R. A threshold (median+2*median absolute deviation) was used to identify boroughs with increasing concentration of unstably housed PWID in 2020-2024 compared to 2015-2019. Among 1607 study visits (2011-2014: 552, 2015-2019: 547, and 2020-2024: 508), the proportion of unsheltered PWID increased to 41.3% in 2020-2024, vs. 26.1% in 2015-2019 and 27.4% in 2011-2014. In 2020-2024, 43.5% of PWID were stably housed vs. 51.4% in 2015-2019 and 53.8% in 2011-2014. Unsheltered PWID were mostly centralized in the downtown area, but precariously housed participants were more dispersed in their locations. We identified six boroughs with increasing concentrations of unstably housed (including precariously housed and unsheltered) PWID, mainly in downtown and adjacent boroughs. In the context of declining housing affordability, an increased proportion of PWID are reporting being unsheltered. Further work is needed to examine transitions from stable and precarious housing to being unsheltered. Services supporting precariously housed people may need to diversify their geographic locations, given this population's more dispersed residential profile.