According to a 1999 report by the Institute of Medicine, as many as 98,000 Americans were dying every year because of medical mistakes. Today, exact figures are hard to come by because states don’t abide by the same reporting guidelines, and few cases gain as much attention as that of Rory Staunton, the 12-year-old boy who died of septic shock this spring after being sent home from a New York hospital. But a reasonable estimate is that medical mistakes now kill around 200,000 Americans every year. That would make them one of the leading causes of death in the United States. Why have these mistakes been so hard to prevent?More Treatment, More Mistakes, july 31 2012, The New York Times.