[1] Karolinska Univ Hosp, Karolinska Inst, Dept Gastroenterol & Hepatol, Stockholm, Sweden
[2] Karolinska Univ Hosp, Karolinska Inst, Dept Med, Clin Epidemiol Unit, Stockholm, Sweden
[3] Sahlgrenska Univ Hosp, Dept Med, Gothenburg, Sweden
[4] Malmo Univ Hosp, Dept Med, Div Gastroenterol & Hepatol, Malmo, Sweden
[5] Univ Lund Hosp, Div Gastroenterol & Hepatol, S-22185 Lund, Sweden
[6] Karolinska Hosp & Inst, Dept Gastroenterol & Hepatol, Stockholm, Sweden