Differential Diagnosis and Heuristics-Reply

Abstract

In Reply.— We agree with Dr Nardone that in medicine the clinician often uses both a depth and breadth approach in evaluating a patient's clinical findings. Using a depth approach, the clinician probes for information in a vertical, aggressive style within one disease in order to confirm or disconfirm his or her primary hypothesis. Using a breadth approach, the clinician probes in a horizontal, cautious style across competing hypotheses in a differential diagnosis. Many of us believe that these depth-breadth strategies are indeed complementary, and that the clinician frequently pursues a sequential pattern in which the initial symptom (eg, pleuritic chest pain) is pursued along a vertical path by asking questions designed to confirm or rule out the primary hypothesis (eg, pulmonary embolism; was the patient immobilized?; are there calf or thigh symptoms?). The clinician may then shift to a broader cautious questioning mode to examine whether another diagnostic hypothesis