Participation in the MOST program is voluntary. However, clients must be over the age of 18 to be involved. Referral can come from the individual or any agency or professional, but it is expected that the individual will make the initial call to speak with a nurse and book the assessment appointment. An appointment for an assessment with a nurse will be made based on preliminary data obtained by telephone. At the initial appointment with the nurse, a complete psycho-social assessment is done. Once suitability has been established, the client will be given an appointment to see the MOST program physician. The client signs a contract that he or she will abide by the rules of the program, with particular reference to behaviour on the premises, and drug monitoring.