Background Research has explored barriers and facilitators to supervised consumption sites (SCS) in Canadian settings. Despite this, little is known about what factors drive individuals to initiate and sustain engagement with SCSs in contexts where multiple SCS options are available, such as Vancouver’s Downtown Eastside (DTES). The aim of this study was to understand the structural, contextual, and operational determinants of regular SCS attendance.

Methods Rapid-ethnographic fieldwork was conducted over a six-week period at an integrated SCS in Vancouver’s DTES. This comprised an initial five-week period of non-participant observation (≈200 hours) followed by a community consultation regarding the research design and question protocols. Qualitative data were then collected through five focus groups (n=25) and 20 semi-structured interviews with regular service attendees.

Results Our findings highlight several important factors related to the determinants of regular service attendance. Firstly, the service had a regular clientele who described their attendance as routinized, credited to four distinct factors: 1) the accessible location, 2) the on-site auxiliary services, 3) the diversity of harm reduction provision, and 4) the atmosphere. Exploring the concept of atmosphere in more depth revealed that it was characterized by the safety, familiarity and inclusivity experienced within the service. Together these factors facilitated a strong sense of belonging in attendees regarding the service and its community of staff and clients.

Conclusion Within the context of an ongoing overdose crisis, our findings highlight SCS service characteristics which facilitate routinized engagement. These insights can inform the development of more effective, client-centred SCSs.