According to a recent report from the Institute of Medicine, it is estimated that:

• 5% of U.S. adults who seek outpatient care each year experience a diagnostic error
• diagnostic errors contribute to approximately 10% of patient deaths
• diagnostic errors account for 6 to 17% of adverse events in hospitals

Source: "Improving Diagnosis in Health Care," Institute of Medicine/the National Academy of Sciences, Report in Brief, September 22, 2015, http://iom.nationalacademies.org/~/media/Files/Report%20Files/2015/Improving-Diagnosis/DiagnosticError_ReportBrief.pdf