[1] Univ Cincinnati, Sch Med, Dept Emergency Med, Cincinnati, OH USA
[2] Univ Cincinnati, Sch Med, Inst Hlth Policy, Cincinnati, OH USA
[3] Univ Cincinnati, Sch Med, Hlth Serv Res, Cincinnati, OH USA
[4] Duke Univ, Med Ctr, Dept Emergency Med, Durham, NC USA
[5] Duke Univ, Med Ctr, Div Nephrol, Durham, NC USA
[6] Duke Univ, Med Ctr, Div Cardiol, Durham, NC 27710 USA
[7] Duke Univ, Med Ctr, Duke Clin Res Inst, Durham, NC 27710 USA
[8] Univ N Carolina, Sch Med, Chapel Hill, NC USA