7 Evaluation of screening programmes

As with other public health interventions, the decision to adopt a screening programme will need to take account of both the benefits and the burdens, including both human and financial costs. A balanced view is called for, and this is best achieved by making explicit the scientific information underpinning the proposed screening programme. In normal medical practice, there is frequently also a conflict between the therapeutic and the iatrogenic, but the detailed justification for preferring a particular medical intervention is often not always made clear. However, in normal medical practice doctors act in response to the patient who seeks alleviation of symptoms, whereas screening is proactive. Consequently, there is a greater obligation to ensure that a proper justification can be made. It is fruitless to try to justify screening in general; each screening programme needs to be considered separately. Some will be found wanting and can be readily discarded. Others will show a clear-cut benefit and, provided sufficient funding were available, could become routine practice. In many cases, however, the balance may be more finely poised, and there is likely to be an element of value judgement.