MedicalResearch.com Interview with: Daniel A. Waxman, MD, PhD Department of Emergency Medicine David Geffen School of Medicine University of California, Los Angeles RAND Corporation Santa Monica, California  MedicalResearch.com: What is the background for this study? What are the main findings? Response: When people talk about medical error, they are usually referring to treatment error—giving the wrong medication, operating on the wrong side of the body, etc.  But many believe that diagnostic error—the failure to diagnose a condition when a patient seeks care—is at least as widespread and consequential a problem.  However, diagnostic errors are intrinsically difficult to measure, since one can rarely prove that a condition was present at the time it was not diagnosed. In this study, we introduce a novel method for measuring how often patients who come to the emergency room with symptoms of an imminent cardiovascular emergency such as acute myocardial infarction (heart attack) are discharged home without a diagnosis. We find that among Medicare patients whose ER visits were attributable to symptoms of an imminent infarction, only about 2.3% were discharged home, and that the figure was under 5% for each of the other four conditions we studied.    However, we also found that these relatively low rates did not improve between 2007 and 2014. (more…)