[1] Baylor Coll Med, Sect Gastroenterol & Hepatol, Dept Med, One Baylor Plaza, Houston, TX 77030 USA
[2] Baylor Coll Med, Dan L Duncan Comprehens Canc Ctr, Houston, TX 77030 USA
[3] Michael E DeBakey VA Med Ctr, Houston VA HSR&D Ctr Innovat Qual Effectiveness &, Dept Med, Houston, TX USA