[1] Baylor Coll Med, Dept Med, Sect Gastroenterol & Hepatol, Houston, TX 77030 USA
[2] Michael E DeBakey VA Med Ctr, Ctr Innovat Qual Effectiveness & Safety, Houston, TX USA
[3] Baylor Coll Med, Dept Med, Houston, TX 77030 USA
[4] Univ Texas Houston, Sch Publ Heath, Dept Epidemiol, Houston, TX USA
[5] Univ Texas Med Branch, Dept Prevent Med & Community Hlth, Off Biostat, Galveston, TX 77555 USA
[6] Baylor Coll Med, Sect Epidemiol & Populat Sci, Houston, TX 77030 USA
[7] Baylor Coll Med, Dan L Duncan Comprehens Canc Ctr, One Baylor Plaza,MS BCM307, Houston, TX 77030 USA