[1] Harvard Univ, Sch Med, Dept Hlth Care Policy, Boston, MA 02115 USA
[2] Harvard Univ, Sch Publ Hlth, Dept Biostat, Boston, MA 02115 USA
[3] Harvard Univ, Sch Publ Hlth, Dept Hlth Policy & Management, Boston, MA 02115 USA
[4] Massachusetts Gen Hosp, Heart Failure Ctr, Boston, MA 02114 USA
[5] Brigham & Womens Hosp, Dept Radiol, Boston, MA 02115 USA