[1] Greater Los Angeles Vet Affairs Healthcare Syst, Los Angeles, CA 90073 USA
[2] Univ Calif Los Angeles, Dept Med, Div Gen Internal Med & Hlth Serv Res, Los Angeles, CA 90095 USA
[3] West Angeles VA Med Ctr, Gen Internal Med 111G, Los Angeles, CA 90073 USA
[4] Univ Calif Los Angeles, Fielding Sch Publ Hlth, Los Angeles, CA USA
[5] RAND Corp, Southern Calif Evidence Based Practice Ctr, Santa Monica, CA 90401 USA
[6] Univ Calif Los Angeles, Louise M Darling Biomed Lib, Los Angeles, CA 90024 USA
[7] Humana Inc, Lexington, KY 40512 USA