Evaluating the benefits of nuclear cardiology.

This paper reviews the role of nuclear cardiology in the context of health care evaluation and resource utilisation. Nuclear cardiology procedures are used to detect disease, to define the extent of disease, to predict the outcome of therapy and to monitor the response to treatment. The evaluation of the effectiveness will depend on the role for which the tests are being used. The evaluation of diagnostic tests most commonly follows the five level Fineberg classification. I) Technical capacity; II) diagnostic accuracy; III) diagnostic impact; IV) therapeutic impact; V) patient outcome. Tests may succeed or fail at each of these hierarchical levels. In addition to the clinical impact which is evaluated, the appropriate use of health care resources has to be considered, i.e. the cost effectiveness of the investigation. For this the costs of diagnosis and treatment in the resources used, together with the direct cost on the patient and patient carers needs to be considered. In addition to these direct costs to the community and to the patient and the carers the secondary downstream costs and opportunity costs have to be taken into account. The common methods for assessing the costs and benefits include cost minimalisation, cost effectiveness, cost utility, and cost benefit studies. The advantages and disadvantages and appropriate use of these methods are reviewed. There are seven clinical methods for evaluating diagnostic tests in nuclear cardiology which are: I) case reports; II) consensus studies; III) databases; IV) case control studies; V) modeling techniques; VI) management impact studies; VII) randomised control trial. Each of these has a role with advantages and disadvantages which are reviewed. It is no long sufficient to investigate the usefulness of a diagnostic test used in nuclear cardiology in isolation but it has to be within the context of the health care system and the resources used.