[1] BETH ISRAEL HOSP, DEPT MED, DIV CARDIOVASC, BOSTON, MA 02215 USA
[2] BETH ISRAEL HOSP, DEPT MED, DIV CLIN EPIDEMIOL, BOSTON, MA 02215 USA
[3] BRIGHAM & WOMENS HOSP, DEPT MED, BOSTON, MA 02115 USA
[4] HARVARD UNIV, SCH MED, BOSTON, MA 02115 USA
[5] HARVARD UNIV, SCH PUBL HLTH, DEPT HLTH POLICY & MANAGEMENT, BOSTON, MA 02115 USA