[1] Temple Univ, Philadelphia, PA 19122 USA
[2] Univ Minnesota, Minneapolis, MN USA
[3] Denver Hlth Med Ctr, Denver, CO USA
[4] Univ Alabama Birmingham, Birmingham, AL USA
[5] Harbor UCLA Med Ctr, Torrance, CA 90509 USA
[6] Univ Alabama Stn, Birmingham, AL USA
[7] Univ Michigan Hlth Ctr, VAMC, Ann Arbor, MI USA
[8] Univ Alabama Birmingham, Birmingham, AL USA
[9] Univ Michigan Hlth Syst, Ann Arbor, MI USA
[10] Natl Jewish Hlth, Denver, CO USA
[11] Temple Univ Hosp & Med Sch, Philadelphia, PA 19140 USA
[12] Cornell Univ, Weill Cornell Med Coll, New York, NY 10021 USA
[13] Univ Calif San Francisco, San Francisco, CA 94143 USA
[14] Minneapolis VA Med Ctr, Minneapolis, MN USA
[15] Johns Hopkins, Baltimore, MD USA
[16] Mayo Clin, Rochester, MN USA
[17] Univ Pittsburgh, Med Ctr, Pittsburgh, PA USA
[18] Brigham & Womens Hosp, Boston, MA 02115 USA
[19] Univ Calif San Francisco, San Francisco, CA 94143 USA
[20] HealthPartners, St Paul, MN USA
[21] Ottawa Hosp, Res Inst, Ottawa, ON, Canada
[22] Providence Heart Lung Inst, Vancouver, BC, Canada