Background: Opiate substitution treatment (OST) is a treatment for people with opioid use disorder, preventing overdose related deaths, giving the patients an opportunity to live functional lifes. Lack of medical adherence within OST is a well known circumstance wich affects the treatment outcome and patients early released from OST suffers a great risk of dying from overdoses. Nurses has shown to play an important role in OST and better knowledge about what effects medical adherence is important for an improved treatment outcome with higher patientretention.

Aim: The aim was to examine medical adherence within OST for better treatment outcome.

Method: Evans systematic review with descriptive design. A four step synthesis of qualitative research

Results: Three teamgroups, each including one main theme with two belonging subthemes, emerged from the result: The meeting with the care system: The importance of knowledge and information, The impact of Nurse-Patient relation. The dream of a normal life: OST as an opsticle, OST as an enabler. Alienation: Stigma, The importance of belonging. In each themegroup a phenomena in common emerged, highlighting adherence to treatment, described in figure 1.

Discussion: The method of choice is discussed regarding its strengths and weaknesses. The result showed that each themegroup, consisting of one main theme and two belonging subthemes, had one phenomena in common. These phenomenas: Participation, Hope and Acceptance, all effected the medical adherence for patients within OST and were discussed together with Barkers tidal model and relevant research.