[1] Norwegian Inst Publ Hlth, Dept Hlth Promot, Bergen, Norway
[2] Norwegian Inst Publ Hlth, Ctr Evaluat Publ Hlth Measures, Oslo, Norway
[3] Helse Fonna HF, Dept Res & Innovat, Haugesund, Norway
[4] Univ Ottawa, Sch Epidemiol & Publ Hlth, Ottawa, ON, Canada
[5] Norwegian Inst Publ Hlth, Ctr Fertil & Hlth, Oslo, Norway
[6] NORCE, Reg Ctr Child & Youth Mental Hlth & Child Welf, Bergen, Norway
[7] Stavanger Univ Hosp, Alcohol & Drug Res Western Norway, Stavanger, Norway
[8] Norwegian Inst Publ Hlth, POB 973 Sentrum, N-5808 Bergen, Norway