Conclusions
In this initial randomized trial of a physician-facing and patient-facing peer comparison and educational intervention, we did not find significant improvement in shared decision-making conversations about medical testing during annual visits. Testing was common during annual examinations and there was evidence of cycles of misunderstanding in which patients and physicians assumed the other party wanted testing, with many patients not fully appreciating potential downsides. To break these cycles, improve conversations around medical tests, and reduce overuse and downstream cascades, future efforts should involve robust, targeted interventions that focus on mitigating physician adoption barriers and further leveraging patient-clinician relationships.