Diagnostic errors are the failure to correctly diagnose a patient’s health condition, and is considered medically negligent. Often, this leads to a worsening of this condition in the patient, in which case the diagnostic error would be considered medical malpractice. It is estimated that between 10-20% of cases are misdiagnosed and that 75% of misdiagnosed cases were the result of medical negligence. Furthermore, with nearly 9,000 internal medicine suits from 1995-2009 being the result of a failure to diagnose, misdiagnosis is the leading cause of medical malpractice suits.
So how common are diagnostic errors according to specialty? In a recent review of 1,877 medical specialty-specific diagnosis-related closed claims from 2007 to 2013, The Doctors Company focused on "alleged diagnosis-related errors and the specific diagnoses that were involved in the claims involving ten medical specialties."
The review found that 31% of the nonsurgical specialty claims were related to diagnosis (which was the number one allegation in nonsurgical specialty claims) and that 11% of the surgical specialty claims were related to diagnosis, which was the third most common allegation in surgical claims.
You can find statistics for each specialty (cardiology, pediatrics, etc.) at this link. The report notes that because many of the problematic diagnoses are found in the top five most common claims across a variety of specialties, "This suggests that knowledge deficiency is not the primary cause of diagnostic error and that other factors play an important role.