When the IOM study, To Err Is Human (report brief), came out in 1999, it caused an uproar with its estimate that as many as 95,000 Americans a year die as the result of preventable medical error. According to HealthGrades, that estimate would have been twice as large if the IOM had included (1) failure to diagnose and treat a serious medical problem in time and (2) unexpected death in a low-risk