[1] Texas A&M Univ, Populat Informat Lab, College Stn, TX USA
[2] Texas A&M Hlth Sci Ctr, Sch Publ Hlth, Dept Hlth Policy & Management, College Stn, TX USA
[3] Texas A&M Univ, Dept Ind & Syst Engn, College Stn, TX USA
[4] UT Southwestern Med Ctr, Div Digest & Liver Dis, Dallas, TX USA
[5] UT Southwestern Med Ctr, 5959 Harry Hines Blvd POB 1 04 420, Dallas, TX 75390 USA