[1] Commonwealth Fund, Int Program Hlth Policy & Practice, New York, NY 10021 USA
[2] Univ Adelaide, Sch Populat Hlth & Clin Practice, Adelaide, SA, Australia
[3] Vet Affairs Palo Alto Hlth Care Syst, Palo Alto, CA USA
[4] Stanford Univ, Ctr Hlth Policy, Stanford, CA 94305 USA
[5] Stanford Univ, Ctr Primary Care & Outcomes Res, Stanford, CA 94305 USA