[1] New York Univ, Div Gastroenterol, Dept Med, Inflammatory Bowel Dis Ctr NYU Langone Hlth,Sch M, New York, NY 10016 USA
[2] Dept Med, Clin Epidemiol Div, Solna, Sweden
[3] Karolinska Inst, Stockholm, Sweden
[4] Stockholm South Gen Hosp, Sachs Children & Youth Hosp, Stockholm, Sweden
[5] Soder Sjukhuset, Karolinska Inst, Dept Clin Sci & Educ, Stockholm, Sweden
[6] Aarhus Univ Hosp, Dept Clin Epidemiol, Aarhus, Denmark
[7] Randers Reg Hosp, Dept Surg, Randers, Denmark
[8] Orebro Univ, Sch Hlth & Med Sci, Fac Med & Hlth, Dept Gastroenterol, Orebro, Sweden
[9] Karolinska Inst, Dept Med Epidemiol & Biostat, Stockholm, Sweden
[10] Orebro Univ Hosp, Dept Pediat, Orebro, Sweden
[11] Univ Nottingham, Sch Med, Div Epidemiol & Publ Hlth, Nottingham, England
[12] Columbia Univ, Coll Phys & Surg, Dept Med, New York, NY USA