Ann Surg 2015 May;261(5):914-9
*Division of General Internal Medicine and Center for Clinical Effectiveness, University of Cincinnati, Cincinnati, OH †Group Health Center for Health Studies, Seattle, WA ‡Department of Gastrointestinal and Endocrine Surgery, University of Texas Southwestern, School of Medicine, Dallas, TX §Kaiser Permanente Southern California, Pasadena, CA ¶Kaiser Permanente Northern California, Oakland, CA ‖Health Partners Institute for Education and Research, Minneapolis, MN **Division of General Surgery, University of Cincinnati Medical Center, Cincinnati, OH.