[1] Univ Tromso, Fac Med, Dept Community Med, Ctr Sami Hlth Res, N-9730 Karasjok, Norway
[2] Inst Populat Based Canc Res, Canc Registry Norway, N-0310 Oslo, Norway
[3] Univ Tromso, Hosp N Norway, Child & Adolescent Psychiat Outpatient Clin, N-9038 Tromso, Norway