[1] Texas Tech Univ, Internal Med, Hlth Sci Ctr El Paso, Paul L Foster Sch Med, El Paso, TX USA
[2] Texas Tech Univ, Pulm & Crit Care Med, Hlth Sci Ctr El Paso, Paul L Foster Sch Med, El Paso, TX USA
[3] Univ Arkansas Med Sci, Gastroenterol, Little Rock, AR 72205 USA
[4] Univ Texas Hlth Sci Ctr San Antonio, Gastroenterol, San Antonio, TX 78229 USA
[5] UCSD, La Jolla, CA USA
[6] Mem Hosp Martinsville & Henry Cty, Internal Med, Martinsville, VA USA
[7] Texas Tech Univ, Dept Biostat, Hlth Sci Ctr El Paso, Paul L Foster Sch Med, El Paso, TX USA
[8] Univ Arizona, Arizona Hlth Sci Ctr, Tucson, AZ USA
[9] Wright Ctr Grad Med Educ, Internal Med, Scranton, PA USA
[10] Mercer Univ, Internal Med, Sch Med, Macon, GA 31207 USA