1. Division of Research, Kaiser Permanente Medical Care Program, Northern California, Oakland, California.
2. Goldman School of Public Policy, University of California at Berkeley, California.
3. University of California at Los Angeles David Geffen School of Medicine, Division of General Internal Medicine and Health Services Research and the UCLA School of Public Health, Los Angeles, California.
4. Roudebush VAMC, Division of General Internal Medicine and Geriatrics, Department of Medicine, Indiana University School of Medicine, and Regenstrief Institute for Healthcare, Inc., Indianapolis, Indiana.