First do no harm: overdiagnosis in Pediatrics.

Many errors can be made in diagnosis: underdiagnosis, misdiagnosis, and overdiagnosis. While underdiagnosis and misdiagnosis are clear errors, in overdiagnosis, a true abnormality is discovered, but detection does not benefit the patient. Harm occurs when patients are further evaluated and treated unnecessarily as a result of making a diagnosis that would never have affected the patient if the diagnosis had not been made. Several phenomena point to potential overdiagnosis: when delayed or missed diagnoses do not result in harm; when there is increased detection of a disease, but no change in the outcome; and when randomized trials show no benefit from the diagnosis. Some might say that there is always benefit in knowing, but the adverse effects of overdiagnosis are well documented. We will need to educate ourselves and our colleagues about the potential for harm from overdiagnosis, and learn how to balance the potential benefit of a diagnosis against the risk of overdiagnosis.