Affiliation: | 1. Kaiser Permanente Washington Health Research Institute, Seattle, Washington;2. Department of Population Medicine, Harvard Medical School, Harvard Pilgrim Health Care Institute, Boston, Massachusetts;3. Department of Radiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina;4. Department of Medicine, University of California at San Francisco, San Francisco, California Department of Epidemiology and Biostatistics, University of California at San Francisco, San Francisco, California General Internal Medicine Section, Department of Veterans Affairs, University of California at San Francisco, San Francisco, California;5. Department of Radiology, University of Washington, Seattle, Washington |