[1] Univ Minnesota, Dept Family Practice & Community Hlth, Sch Med, Minneapolis, MN 55414 USA
[2] Univ Minnesota, Sch Publ Hlth, Div Hlth Serv Res & Policy, Minneapolis, MN 55455 USA
[3] Emory Univ, Rollins Sch PUbl Hlth, Dept Hlth Policy & Management, Atlanta, GA 30322 USA
[4] Univ Wisconsin, Sch Med, Dept Prevent Med, Madison, WI USA