Table 3.

Working process evaluation framework

Research domain		Research questions
Implementation	Fidelity & quality	How did implementation of SIPP intervention vary from what was planned, i.e. (a) recruitment of PWUC at all sites, (b) training and protocols delivered, (c) provision of SIPP kits, (d) active engagement of peer networks, (e) SIPP harm reduction materials developed and used
What is implemented and how?		What were the barriers and facilitators to implementation fidelity?
		What adaptations were made?
	Coverage (reach & dose)	How many: (a) PWUC were approached across all sites, (b) PWUC took up SIPP kits and/or peer-led harm reduction training (c) PWUC were referred or linked to specialist drug services, and (d) local law enforcement and/or government authorities maintained support
		What were the barriers and facilitators to each of the above?
Mechanism of impact	Acceptability & feasibility	Which components of the intervention were best accepted and adopted by PWUC, peer-network members, providers, and health system/policy stakeholders? What were the experiences and perceptions of PWUC who were actively, somewhat or not at all engaged with harm reduction and SIPP uptake? What were the challenges and barriers faced?
How does intervention lead to change?	Interactions & consequences	How did various components of the intervention interact (i.e. SIPP kit provision, peer-network harm reduction outreach, uptake of specialist drug services)?
		Were there any unanticipated pathways or consequences?
Context	Proximal and distal	What social, cultural, political, and logistical factors impede or facilitate (or were affected by) how the intervention was implemented across the different sites
How context affects implementation & outcomes?”		What were contextual reasons for adaptations to the intervention and its delivery?