Intervention fidelity All staff will have an assessment of a patient audiotaped and assessed by the researcher for use of UBC using the Peer Proficiency Assessment (PEPA) (Maestroleo et al 2009). This process will be explained to patients when they first consent to being part of the study and again before the recording takes place. The audio-recorder will be encrypted and the recordings will be analysed using the PEPA tool, by the investigator, and then deleted. The PEPA tool was developed to evaluate the fidelity to use of MI skills in undergraduate peer counsellors. PEPA is a valid tool which is simple to use and demonstrates high inter-rater reliability between master coders, experienced peer counsellors and minimally trained peer counsellors (Mastroleo et al 2009).