1. Center for Healthcare Organization and Implementation Research (CHOIR), VA Boston Healthcare System, Boston, Massachusetts
2. Department of Surgery, Boston University School of Medicine, Boston, Massachusetts
3. Center for Access and Delivery Research and Evaluation, Iowa City VA Health Care System, Iowa City, Iowa
4. Department of Internal Medicine, University of Iowa, Iowa City
5. Department of Medicine, VA Boston Healthcare System, Boston, Massachusetts
6. Harvard Medical School, Boston, Massachusetts