[1] Akershus Univ Hosp, Pulm Dept, N-1478 Lorenskog, Norway
[2] Univ Oslo, Inst Clin Med, N-0450 Oslo, Norway
[3] Univ Oslo, Inst Basic Med Sci, Dept Behav Med, N-0317 Oslo, Norway
[4] Ostfold Hosp Trust Kalnes, Haematol & Oncol, N-1714 Gralum, Norway
[5] Norwegian Ctr Violence & Traumat Stress Studies, N-0484 Oslo, Norway
[6] Akershus Univ Hosp, Hlth Serv Res Unit, N-1478 Lorenskog, Norway