1. From Kaiser Permanente Washington Health Research Institute, University of Washington, and University of Washington School of Medicine, Seattle, Washington; Kaiser Permanente Center for Health Research, Portland, Oregon; University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania; University of California, Irvine School of Medicine, Orange, California; Brown University, Providence, Rhode Island;
2. Harvard Pilgrim Health Care Institute and Harvard Medical School, Boston, Massachusetts; Hospital Corporation of America, Nashville, Tennessee; Texas A&M College of Medicine, Houston, Texas; CHB Wordsmith, Raleigh, North Carolina; University of Texas Southwestern Medical Center, Dallas, Texas; and Duke University School of Medicine, Durham, North Carolina.