[1] Columbia Univ, Coll Phys & Surg, Celiac Dis Ctr, Dept Med, New York, NY 10027 USA
[2] Karolinska Univ Hosp, Dept Med, Clin Epidemiol Unit, SE-17177 Stockholm, Sweden
[3] Karolinska Inst, SE-17177 Stockholm, Sweden
[4] Uppsala Univ, Dept Surg Sci, Sect Orthopaed, SE-75105 Uppsala, Sweden
[5] Orebro Univ Hosp, Dept Pediat, SE-70182 Orebro, Sweden