Code category	Parent code	Child code
Outer setting/implementation context	Barriers to care	Budget for interventions Lack of access to care Lack of stability in care Negative feelings about first responders Stigma
	Facilitators to care	Positive feelings about first responder services Low/No barrier access Non-stigmatising environment and rapport building Services brought to PWUD Trauma-informed care Effective first responder communication style
Intervention characteristics	N/A	Buprenorphine HIV/HCV Testing Leave behind naloxone (LBN)
Characteristics of individuals	Perceptions of buprenorphine	Ambivalence toward buprenorphine Interested in buprenorphine Not interested in buprenorphine
	Perceptions of HIV/HCV testing	Ambivalence toward HIV/HCV testing Interested in HIV/HCV testing Not interested in HIV/HCV testing
	Perceptions of LBN	Ambivalence toward LBN Interested in LBN Not interested in LBN
Inner setting	N/A	Characteristics of personal drug use Experiences with overdose Perceptions of first responder roles Perceptions of police Scope of first responder services and mission
Process	Implementation recommendations	Buprenorphine HIV/HCV Testing LBN
	Implementers	Paramedics should provide intervention Firefighters should provide intervention Mobile/outreach clinic should provide intervention Paramedics should not provide intervention Firefighters should not provide intervention Mobile/outreach clinic should not provide intervention Police should not provide intervention Peers should provide intervention