Background: Opioid agonist therapy (OAT) has been severely disrupted by the COVID-19 pandemic. The risks of opioid withdrawal, overdose, and diversion have increased, so there is an urgent need to adapt OAT to best support people who use drugs (PWUD). This review examines the views and experiences of PWUD, health care providers, and health system administrators on OAT during major disruptions to medical care to inform appropriate health system responses during the current pandemic and beyond.

Methods: We conducted a systematic review and qualitative evidence synthesis. We searched three comprehensive datasets for qualitative and mixed-methods studies that examined OAT in the context of major disruptions such as natural disasters, and analyzed included studies using thematic analysis and the constant comparative method. We used conceptual frameworks of health systems resilience and adaptive systems to interpret our findings.

Results: We included 10 studies published between 2002 and 2020 that examined OAT in the context of hurricanes, earthquakes, and terrorist attacks. We organized our results into three themes: uncertainty, inconsistency, and vulnerability; regulatory inflexibility; and lack of coordination. The highly regulated but poorly coordinated systems of OAT provision lacked flexibility to adapt to major disruptions, thereby manufacturing vulnerability for both PWUD and health workers.

Conclusions: OAT programs must be resilient and adaptable to face major disruptions while maintaining quality care. Our findings provide guidance to develop and implement innovative strategies that increase the adaptive potential of OAT programs while focusing on the needs of PWUD.