title: Opioid substitution therapy: Lowering the treatment thresholds.
abstract: BACKGROUND
  Opioid substitution therapy (OST) has been established as the gold standard in treating opioid use disorders. Nevertheless, there is still a debate regarding the qualitative characteristics that define the optimal OST intervention, namely the treatment threshold. The aim of this review is twofold: first, to provide a summary and definition of "treatment thresholds", and second, to outline these thresholds and describe how they related to low and high threshold treatment characteristics and outcomes.
  
  
  METHODS
  We searched the main databases of Medline, PubMed, PsycInfo, EMBASE, CINAHL and the Cochrane Library. Original published research papers, reviews, and meta-analyses, containing the eligible keywords: "opioid substitution", "OST", "low threshold", "high threshold" were searched alone and in combination, up to June, 2015.
  
  
  RESULTS
  Treatment thresholds were defined as barriers a patient may face prior to and during treatment. The variables of these barriers were classified into treatment accessibility barriers and treatment design barriers. There are increasing numbers of studies implementing low threshold designs with an increasing body of evidence suggesting better treatment outcomes compared to high threshold designs.
  
  
  CONCLUSIONS
  Clinical characteristics of low threshold treatments that were identified to increase the effectiveness of OST intervention include increasing accessibility so as to avoid waiting lists, using personalized treatment options regarding medication choice and dose titration, flexible treatment duration, a treatment design that focuses on maintenance and harm reduction with emphasis on the retention of low adherence patients.
authors.affiliation: St George's University of London, Medical School at the University of Nicosia, Agiou Nikolaou Street 93, Engomi, 2408 Nicosia, Cyprus; Department of Addiction Psychiatry, Athalassa Psychiatric Hospital, Cyprus Mental Health Services, Leoforos Lemesou 199/2, 1452 Nicosia, Cyprus.
authors.forename: Georgios
authors.initials: G
authors.lastname: Kourounis
authors.affiliation: St George's University of London, Medical School at the University of Nicosia, Agiou Nikolaou Street 93, Engomi, 2408 Nicosia, Cyprus; Department of Addiction Psychiatry, Athalassa Psychiatric Hospital, Cyprus Mental Health Services, Leoforos Lemesou 199/2, 1452 Nicosia, Cyprus.
authors.forename: Brian David Wensley
authors.initials: BD
authors.lastname: Richards
authors.affiliation: Cyprus Anti-Drugs Council, Leoforos Lemesou 130, City Home 81, 2015 Strovolos, Cyprus.
authors.forename: Evdokia
authors.initials: E
authors.lastname: Kyprianou
authors.affiliation: Cyprus Anti-Drugs Council, Leoforos Lemesou 130, City Home 81, 2015 Strovolos, Cyprus.
authors.forename: Eva
authors.initials: E
authors.lastname: Symeonidou
authors.affiliation: Department of Psychiatry, School of Medicine, National and Kapodistrian University of Athens, 72, 74, Vassil. Sophias Avenue, 11528 Athens, Greece.
authors.forename: Minerva-Melpomeni
authors.initials: MM
authors.lastname: Malliori
authors.affiliation: St George's University of London, Medical School at the University of Nicosia, Agiou Nikolaou Street 93, Engomi, 2408 Nicosia, Cyprus; Department of Addiction Psychiatry, Athalassa Psychiatric Hospital, Cyprus Mental Health Services, Leoforos Lemesou 199/2, 1452 Nicosia, Cyprus. Electronic address: lsamartzis@med.uoa.gr.
authors.forename: Lampros
authors.initials: L
authors.lastname: Samartzis
mesh_terms: D002047:Buprenorphine / Q000627:therapeutic use*; D006297:Health Services Accessibility; D006801:Humans; D008691:Methadone / Q000627:therapeutic use*; D009294:Narcotics / Q000627:therapeutic use; D058850:Opiate Substitution Treatment / Q000379:methods*; D009293:Opioid-Related Disorders / Q000188:drug therapy*; D010349:Patient Compliance; D014850:Waiting Lists
chemical_list: D009294:Narcotics; D002047:Buprenorphine; D008691:Methadone
keywords: Addiction; Buprenorphine; Cyprus; Drugs; Harm reduction; Heroin; Methadone; OST; Opioid; Policy; Substitution; Threshold