A medical error is a preventable adverse effect of care ("iatrogenesis"), whether or not it is evident or harmful to the patient. This might include an inaccurate or incomplete diagnosis or treatment of a disease, injury, syndrome, behavior, infection, or other ailment. Definitions The word error in medicine is used as a label for nearly all of the clinical incidents that harm patients. Medical errors are often described as human errors in healthcare. Whether the label is a medical error or human error, one definition used in medicine says that it occurs when a healthcare provider chooses an inappropriate method of care, improperly executes an appropriate method of care, or reads the wrong CT scan. It has been said that the definition should be the subject of more debate. For instance, studies of hand hygiene compliance of physicians in an ICU show that compliance varied from 19% to 85%. The deaths that result from infections caught as a result of treatment providers improperly executing an appropriate method of care by not complying with known safety standards for hand hygiene are difficult to regard as innocent accidents or mistakes. There are many types of medical error, from minor to major, and causality is often poorly determined. There are many taxonomies for classifying medical errors. Definitions of diagnostic error There is no single definition of diagnostic error, reflecting in part the dual nature of the word diagnosis, which is both a noun (the name of the assigned disease; diagnosis is a label) and a verb (the act of arriving at a diagnosis; diagnosis is a process). At the present time, there are at least 4 definitions of diagnostic error in active use: Graber et al. defined diagnostic error as a diagnosis that is wrong, egregiously delayed, or missed altogether. This is a 'label' definition, and can only be applied in retrospect, using some gold standard (for example, autopsy findings or a definitive laboratory test) to confirm the correct diagnosis. Many diagnostic errors fit several of these criteria; the categories overlap. There are two process-related definitions: Schiff et al. defined diagnostic error as any breakdown in the diagnostic process, including both errors of omission and errors of commission. Similarly, Singh et al. defined diagnostic error as a 'missed opportunity' in the diagnostic process, based on retrospective review. In its landmark report, Improving Diagnosis in Health Care, The National Academy of Medicine proposed a