[1] RAND Corp, RAND Ctr Causal Inference, 4570 5th Ave,Suite 600, Pittsburgh, PA 15213 USA
[2] RAND Corp, Santa Monica, CA USA
[3] Univ Southern Calif, Keck Sch Med, Los Angeles, CA USA
[4] AltaMed Hlth Serv, Los Angeles, CA USA
[5] Univ Calif Los Angeles, Dept Med, Div Gen Internal Med & Hlth Serv Res, Los Angeles, CA 90024 USA