Clinical Decision Making in Relation to Laboratory Investigation: The Role of the Computer

Abstract

A clinician must consider laboratory investigations as extensions of his own clinical skills in elucidating symptoms and signs when he has to make decisions for the diagnosis and management of an individual patient. The clinician may request investigations for reasons other than testing the patient’s presenting condition. He may be examining a selected group of apparently healthy subjects for the presence of undiagnosed disease — population screening. Alternatively, a set of tests, whose selection can depend on the design of the local multichannel analyser, may be done on an individual patient, and these examine for a wide variety of possible abnormalities that are not related to the presenting condition — profiling. The general heading, investigations, includes as well as tests done in pathology departments, X-rays and other forms of medical imaging, and many others; but the examples here will mainly be drawn from the work of the chemical pathology department. This branch of medical science provides assistance to clinicians by the selection, performance, and interpretation of assays of the concentration or activity of endogenous or exogenous chemical compounds, individually or in groups, in body fluids and tissues. Thereby one may be able to deduce alterations of rates of absorption or excretion, or of anabolism and catabolism, or of secretion, or disturbances of the steady state, that can be causing or may result from an altered clinical state.