[1] Leiden Univ, Med Ctr, Dept Gastroenterol & Hepatol, NL-2300 RA Leiden, Netherlands
[2] Univ Groningen Hosp, Groningen, Netherlands
[3] Univ Rotterdam Hosp, Rotterdam, Netherlands
[4] Leiden Univ, Med Ctr, Dept Clin Epidemiol, NL-2300 RA Leiden, Netherlands