Clinical Diagnostic Reasoning: a novel online tutorial system for interactive learning

The Four Columned Approach to Clinical Diagnosis: One of the real problems in making clinical diagnosis is the amount of clinical information we have to digest, such that it is often difficult to see the wood for the trees. Accordingly, it is often hard to make a diagnosis all-of-a-piece " by any "inductive " or other process of reasoning. With experience you will learn to recognize different disease patterns and readily be able to make a clinical diagnosis in those cases. But pattern-recognition is fraught with pitfalls because so often individual cases depart significantly from the classical. Besides pattern recognition requires experience and so is of little value to those in learning. Also it is often less than fully descriptive e.g. 'myocardial infarction'. Because of these factors the approach here is to handle the clinical information within a small number of separate categories each largely independent but which when put together severally describe all aspects of the condition or diagnosis. The following are the four categories: WHERE is the problem? = ANATOMICAL DIAGNOSIS = the anatomical system involved. WHAT is the general pathological nature of the condition? = PATHOLOGICAL DIAGNOSIS HOW does it affect the patient? = PHYSIOLOGICAL DIAGNOSIS = functional consequences of the condition. WHY did the patient get it? = AETIOLOGICAL DIAGNOSIS = background cause. Subsumed under this category is also the question of WHO has the condition and why it occurred WHEN it did. The WHO relates to the type of patient concerned in particular to the social and psychological contexts of the presentation. The WHEN aims to focus on its precipitating factors. The value of the four-column approach is that it allows you to focus down within each category on much less than the total body of information and thereby give you a much greater chance of reaching the correct conclusion. Each of the categories contributes and when taken together they severally describe all the elements of clinical diagnosis. By contrast when the pattern-recogniser pins some off-the-rack diagnostic label on a patient it so often lacks one or other of these categories particularly the Functional and Aetiological ones. Thus we often hear that a patient has had an 'acute myocardial infarct' (Anatomical and general Pathological diagnoses) but where is the comment about how this has affected him functionally (did he have secondary heart failure or ventricular dysrhythmias for example?); and what were the long-term factors predisposing to his condition as well as the more recent ones precipitating it (Aetiological diagnosis) - in this case was there preexisting hypertension predisposing to atheroma and some stressful life event precipitating the episode itself? The present approach allows you to 'tailor-make' a diagnosis (Dx) to the individual patient as you go along rather than force him into some pre-conceived diagnostic pigeon hole read about in some text book."