Table 1 Trial inclusion and exclusion criteria

Homeless (living in temporary accommodation, no fixed abode or rough sleeping) [37]

and

Aged 18 years or over

and

One or more non-prescribed drug overdoses in past 6 months confirmed by self-report and witnessed overdose/ambulance call out/emergency department (ED) visit/naloxone use

Living in residential or community-based rehabilitation facility which has direct access to in-house medical and nursing care

or

Unable to give written informed consent