The 1999 report To Err is Human: Building a Safer Health System exposed the issue of patient safety in health care and was the first in a series of reports from the Institute of Medicine’s Health Care Quality Initiative to assess and improve the nation’s quality of care.  A new report in that series from the National Academies of Sciences, Engineering, and Medicine examines inaccurate or delayed diagnoses — known as diagnostic errors — in health care and provides recommendations on how to improve diagnosis and reduce diagnostic errors.