A new study shows that  doctors make diagnostic errors in about 5% of patients annually, translating to 12 million a year. Researchers examined three studies through chart review and found missed opportunities to make a timely and correct diagnosis based on the available evidence.  According to the data, approximately half of those errors are potentially harmful to patients.

Diagnostic errors are the leading cause of successful medical malpractice claims, and are the most common, most costly and most dangerous of medical mistakes, according to  BMJ Quality & Safety.  Researchers analyzed 350,706 paid claims from the National Practitioner Data Bank from 1986 to 2010 and found diagnostic errors represented 28.6 percent of the claims and accounted for the highest proportion of total payments-35.2 percent or $38.8 billion.