Misdiagnosis leading to incorrect treatment is an example of which type of medical error?

• A. Mistake
• B. Slip/Lapse
• C. Violation
• D. Unknown

Answer: (A)

Understanding the different ways medical errors happen often comes down to where the fault lies: in the decision-making process or in the execution of a plan. A misdiagnosis followed by inappropriate treatment shows the plan itself was flawed from the start—the diagnosis was incorrect, so the chosen treatment was based on a wrong premise. That kind of error is a mistake (a cognitive error in forming the diagnostic plan). If the clinician had correctly diagnosed but then accidentally performed the wrong action, that would be a slip or lapse. A violation would involve knowingly ignoring standard procedures. So, misdiagnosis leading to incorrect treatment best fits a mistake.