[1] VICTORIA GEN HOSP, HALIFAX B3H 2Y9, NS, CANADA
[2] UNIV N CAROLINA, DEPT BIOSTAT, CHAPEL HILL, NC USA
[3] MONTREAL HEART INST, RES CTR, MONTREAL, PQ, CANADA
[4] UNIV ALABAMA, BIRMINGHAM, AL USA
[5] WESTCHESTER MED CTR, HAWTHORNE, NY USA
[6] MICHIGAN STATE UNIV, E LANSING, MI 48824 USA
[7] OREGON HLTH SCI UNIV, PORTLAND, OR USA
[8] VET AFFAIRS MED CTR, PORTLAND, OR USA
[9] BUFFALO GEN HOSP, BUFFALO, NY 14203 USA
[10] UNIV MICHIGAN HOSP, ANN ARBOR, MI 48109 USA
[11] BROCKTON W ROXBURY VET AFFAIRS MED CTR, BOSTON, MA USA
[12] HARVARD UNIV, SCH MED, BOSTON, MA USA
[13] BAYLOR COLL MED, HOUSTON, TX USA
[14] MCMASTER UNIV, SCH MED, HAMILTON, ON, CANADA