[1] BETH ISRAEL HOSP, DEPT MED, DIV CLIN EPIDEMIOL & GEN MED & PRIMARY CARE, BOSTON, MA 02215 USA
[2] HARVARD UNIV, SCH MED, BOSTON, MA 02115 USA
[3] CHARLES A DANA RES INST, BOSTON, MA 02215 USA
[4] BETH ISRAEL HOSP, HARVARD THORNDIKE LAB, BOSTON, MA 02215 USA
[5] BETH ISRAEL HOSP, DEPT NURSING, BOSTON, MA 02215 USA
[6] METROHEALTH MED CTR, DEPT MED, CLEVELAND, OH 44106 USA
[7] METROHEALTH MED CTR, DEPT NURSING, CLEVELAND, OH 44106 USA
[8] DUKE UNIV, MED CTR, DEPT PULM MED, DURHAM, NC 27706 USA