Healthcare utilization and mortality after overdose prevention site closure: A linked cohort analysis using segmented...

Area of Science:

• Public Health
• Addiction Medicine
• Health Services Research

Background:

• Evidence on supervised drug consumption services (SDC) impacts, especially during service withdrawal, is mixed.
• Few studies utilize individual-level, linkable health data to assess these impacts.
• The Red Deer overdose prevention site (OPS) in Alberta, Canada, was scheduled for closure, offering a unique study opportunity.

Purpose of the Study:

• To examine changes in opioid agonist therapy (OAT) dispensing among identifiable OPS clients following the Red Deer OPS closure announcement and cessation.
• To assess changes in acute healthcare utilization and mortality among these clients.

Main Methods:

• Retrospective cohort study using linked provincial administrative health data.
• Segmented difference-in-differences interrupted time-series (DID-ITS) design comparing Red Deer OPS clients with clients from a continuously operating Lethbridge OPS.
• Within-site interrupted time-series (ITS) models for Red Deer-only analyses.

Main Results:

• Following the closure, the proportion of Red Deer clients on OAT increased, exceeding that of Lethbridge clients (16.1% vs. 14.4%, P < 0.021).
• No statistically significant differences were observed in emergency department visits or suspected opioid-related emergency medical services events.
• Mortality events were rare, with no statistically detectable increase observed during the follow-up period.

Conclusions:

• The Red Deer OPS closure was associated with increased OAT dispensing among its users.
• Short-term effects on acute healthcare utilization and mortality appear stable but require longer follow-up for conclusive results.
• Individual-level health data are crucial for evaluating SDC service withdrawal impacts.