BACKGROUND: Homeless people have poor health indices and poor access to healthcare. Their health service utilization (HSU) is typified by late illness presentations; poor attendance rates at appointments; low usage of primary-care services and outpatient departments; and high utilization of Emergency Departments and Inpatient services. Why homeless people have these particular HSU patterns is poorly understood.

AIM: This research sought to explore barriers to health-service usage for homeless people.

DESIGN & SETTING: The author conducted critical realist ethnography over 13 months in Dublin with three services for homeless people (a food-hall, a drop-in centre and on outreach with a rough-sleeper team) and an outreach service for rough sleepers.

METHODS: Ethnographic research was supplemented with focus groups of hospital doctors and homeless people; and 47 semi-structured interviews with homeless people. The epistemological framework was critical realism.

RESULTS: One of the factors identified in the research as contributing to the HSU pattern of homeless people were recurrent interactions between health professionals and patients whereby patients were either excluded or discouraged from attending the health service or self-excluded themselves from that or other such services. These interactions were described as Conversations of Exclusion. Four such conversations were described, the Benzodiazepine Conversation; the Mistrustful Conversation; the Blaming Conversation; and the Assertive Conversation.

CONCLUSIONS: There are certain recurrent interactions between homeless people and doctors that result in the exclusion of the homeless people from the health-service.