[1] Norwegian Inst Publ Hlth, Dept Alcohol Tobacco and Drugs, POB 222, N-0213 Oslo, Norway
[2] Innlandet Hosp Trust, Norwegian Natl Advisory Unit Concurrent Subst Abus, Kjonerud Kompetansesenter, Lovstadveien 7, N-2312 Brumunddal, Norway
[3] UiT Arctic Univ Norway, Inst Clin Med, N-9037 Tromso, Norway
[4] Inland Norway Univ Appl Sci, Fac Social & Hlth Sci, POB 400, N-2418 Elverum, Norway
[5] Stavanger Univ Hosp, Ctr Alcohol & Drug Res, POB 8100, N-4068 Stavanger, Norway
[6] Univ Stavanger, Fac Hlth Sci, Telegrafdirektor Heftyes Vei 73, N-4021 Stavanger, Norway
[7] St Olavs Univ Hosp, Ctr Obes Res, Clin Surg, Postboks 3250, N-7006 Trondheim, Norway
[8] Norwegian Univ Sci & Technol, Dept Clin & Mol Med, N-7491 Trondheim, Norway
[9] Western Norway Univ Appl Sci, Fac Hlth & Social Sci, Dept Hlth & Caring Sci, Svanehaugvegen 1, N-6812 Forde, Norway
[10] Forde Hosp Trust, POB 1000, N-6807 Forde, Norway
[11] Norwegian Inst Publ Hlth, PO Box Norwegian Postboks 222, N-0213 Oslo, Norway