The seminal 1999 Institute of Medicine study estimated that as many as 98,000 patients may die each year due to preventable errors, a number that has entered the popular lexicon. However, this study found that preventable adverse events may actually result in much more harm. Based on analysis of four studies using the Global Trigger Tool, the study concludes that between 210,000 and 400,000 patients experience harm contributing to their death each year. Although the accuracy of the Global Trigger Tool for assessing preventability of harm has been questioned, other studies have also concluded that the overall incidence of preventable adverse events has likely not improved over the past decade.