[1] VA Greater Los Angeles HSR&D Ctr Healthcare Innov, West Los Angeles, CA USA
[2] Univ Calif Davis, Dept Econ, Davis, CA USA
[3] UCLA Fielding Sch Publ Hlth, Dept Hlth Policy & Management, UCLA Ctr Hlth Policy Res, Los Angeles, CA USA
[4] UCLA Fielding Sch Publ Hlth, David Geffen Sch Med UCLA, Div Gen Internal Med & Hlth Serv Res, Dept Hlth Policy & Management, Los Angeles, CA USA