Introduction
Medical test overuse is a costly and intractable problem.One approach to improve medical testing decisions is to encourage patients and clinicians to have routine shared decision-making conversations about any medical test under consideration. Although shared decision-making has largely been studied—and linked to better outcomes—for major decisions such as orthopedic surgery,We conducted a randomized clinical trial of a scalable, patient and physician-targeted intervention to promote high-quality conversations about the role and consequences of medical tests across 14 primary care clinics at an academic medical center. This just-in-time peer comparison and educational intervention was previously developed through user-centered design including multiple rounds of engagement with patients and clinicians.