1. Division of General Internal Medicine, University of Colorado School of Medicine at the Anschutz Medical Campus, Aurora, Colorado, USA;
2. Institute for Health Research, Kaiser Permanente Colorado, Aurora, Colorado, USA;
3. Colorado School of Public Health, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA;
4. Division of Geriatric Medicine, University of Colorado School of Medicine at the Anschutz Medical Campus, Aurora, Colorado, USA;
5. VA Eastern Colorado Health Care System, Denver, Colorado, USA;
6. Division of General Internal Medicine and Health Services Research, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA;
7. Department of Family Medicine, University of Colorado School of Medicine at the Anschutz Medical Campus, Aurora, Colorado, USA