[1] Innlandet Hosp Trust, Norwegian Natl Advisory Unit Concurrent Subst Abu, Brummundal, Norway
[2] UiT Arctic Univ Norway, Fac Hlth Sci, Dept Clin Med, Tromso, Norway
[3] Univ Oslo, Norwegian Ctr Addict Res, Oslo, Norway
[4] Akershus Univ Hosp, Hlth Serv Res Unit, Lorenskog, Norway
[5] Univ South Eastern Norway, Ctr Care Res, Porsgrunn, Norway
[6] Univ Hosp North Norway, Divison Mental Hlth & Addict, Tromso, Norway