Table 3.

Selected quotes emphasized by the co-researchers in the focus group, online platform, or final questionnaire

Theme	Quotes
Interaction with residents	The project team should include people who have already built up trust to the homeless community
	Be prepared for multiple languages and guarantee barrier-free communication
	Use audio- and video formats for provision of information
	Informed consent and sample collection may be influenced by intoxication of residents
	It's a nice way to talk to people you didn't know before. Many were happy about the conversation
Willingness for participation	During the cold season, homeless people might have other priorities, consider needs and daily routine of the residents in the planning
Specimen collection	Patience and understanding for repeated instructions are needed
	With more flexible times of sample collection, we could have reached more residents
	Without assistance, the collection would have not been possible for several residents
Staff and workload	Good and continuous communication among the health workers, social workers and language mediators, as well as supervision was essential
	Additional staff is needed due to high workload of monitoring activities
	Benefits for residents and staff should be identified and emphasised. The monitoring gave me a feeling of security in the shelter
Ethical considerations	Information on data use and consequences of a positive test result should be transparent
	Accept a “no”, take people as they are