[1] Hippokrateion Hosp, Dept Internal Med 4, Thessaloniki, Greece
[2] Rhodes Hosp, Dept Internal Med 1, Rhodes, Greece
[3] Hippokrateion Hosp, Dept Internal Med 2, Athens, Greece
[4] Univ Thessaly, Sch Med, Dept Med, Larisa, Greece
[5] Univ Thessaly, Res Lab Internal Med, Larisa, Greece
[6] Democritus Univ Thrace, Sch Med, Dept Internal Med 1, Alexandroupolis, Greece
[7] AHEPA Hosp, Dept Gastroenterol, Internal Med Clin 1, Thessaloniki, Greece
[8] Univ Patras, Sch Med, Dept Gastroenterol, Patras, Greece
[9] Nikaia Hosp, Dept Internal Med 2, Athens, Greece
[10] Univ Hosp ATTIKON, Dept Internal Med, Athens, Greece
[11] Laiko Univ, Gen Hosp, Dept Internal Med Propaedeut, Athens, Greece
[12] Laikon Gen Hosp, Physiopathol Dept, Athens, Greece
[13] Papageorgiou Gen Hosp, Dept Gastroenterol, Thessaloniki, Greece
[14] Univ Thessaly, Sch Med, Dept Biomath, Larisa, Greece
[15] Tufts Univ, Sch Med, Tufts Med Ctr, Inst Clin Res & Hlth Policy Studies, Boston, MA 02111 USA
[16] Roche Hellas, Med Affairs, Athens, Greece