ABSTRACT
Diagnostic processing can involve a number of investigations ranging from simple urine dipsticks to more elaborate technologies such as radiology, endoscopy, physiological and pathological testing. However, primary care diagnostics is not simply about assimilating masses of information from as many of these tests as possible in order to detect or to exclude a disorder, it is also about considering the risks and the benefits of any investigation from the perspective of the patient. It is important to appreciate that, for many investigations, 'normal' is defined in relation to the overall distribution of the results obtained from a number of individuals. All investigations must also be carefully considered in relation to the information already obtained from the symptoms, the past medical history and the clinical examination that will have produced a post-examination probability of disease. From the patient's perspective, the concern is that they may be subjected to increasingly invasive and somewhat risky investigations.
