ABSTRACT
Primary care diagnostics is about repositioning the patient and their interaction with the primary care physician back at the heart of the diagnostic process. By focusing on the technology rather than the patient, there is often a failure to appreciate that, in most circumstances diagnosis involves a carefully specified sequence of actions rather than a single investigation. Moreover, important clinical information can be obtained from a careful assessment of a patient's symptoms, their past medical history, and the clinical examination in addition to biochemical, pathological, physiological and radiological tests. Diagnostic processing commences when a patient presents with a known abnormality such as a symptom, a sign or an incidental test finding to a primary care physician. Validity is an assessment of the degree to which an item of clinical information relates to the 'truth' and one of the difficulties of using any such information is that it always exhibits less than perfect validity.
