1 Department of Vascular Surgery, The Permanente Medical Group, South San Francisco, CA; Division of Research, Kaiser Permanente Northern California, Oakland, CA.
2 Division of Research, Kaiser Permanente Northern California, Oakland, CA; Departments of Medicine and Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA.
3 Division of Research, Kaiser Permanente Northern California, Oakland, CA; Department of Health System Science, Kaiser Permanente Bernard J. Tyson School of Medicine, Pasadena, CA.