1. From the Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine (M.T.W., H.C.P., J.D.C.), and Section of Thoracic Surgery, Department of Surgery (J.D.C.), University of Michigan, 39160 Taubman Center, 1500 East Medical Center Drive SPC 5360, Ann Arbor, MI 48109-5361; and VA Center for Clinical Management Research, Ann Arbor, MI (H.C.P.).