Duagnosis: Locating Clinical Uncertainty in the Diagnostic Framework

Clinical reasoning research has predominantly operated within a single epistemological system. The prevailing response to clinical uncertainty in primary care has been to cultivate tolerance, embrace ambiguity, or learn to navigate it: each treats uncertainty as inherent to the encounter. We propose a complementary move. Much of what is called clinical uncertainty may be attributed less to the patient's condition than to the reach of the diagnostic framework through which the clinician reasons. We introduce the concept of duagnosis (dual + gnosis, 'knowing'): the clinical cognition in which two independent diagnostic systems are simultaneously activated within a single clinician's reasoning.

Conceptual analysis proceeding through concept definition, differentiation from neighbouring frameworks, development of the epistemological argument, and institutional comparison across East Asia. The analysis draws on clinical reasoning research, the philosophy of medicine, evidence on the care of persistent physical symptoms, and comparative scholarship on traditional medicine.

The core contribution is epistemological: what one framework cannot formulate may resolve into a recognisable, actionable pattern in another, so that uncertainty is partly a property of the framework and not only of the patient. Duagnosis can be stated in two versions: a broad sense continuous with family medicine's plural readings of the patient, and a strict sense in which the criteria of evidence themselves change. An East Asian institutional comparison shows that Japan's unified medical licence locates diagnostic duality within individual clinician cognition for every physician, a capacity medical education has not cultivated.

Expanding the diagnostic repertoire, not merely tolerating uncertainty, can reduce the proportion of presentations for which no clinical formulation exists. Locating uncertainty partly in the reach of the framework, rather than in the patient, is a reframing that applies beyond any one health system, with implications for communication and referral.