Evaluating the costs and benefits of a diagnostic technology: the case of upper gastrointestinal endoscopy.

Medical technology assessment has been proposed as a way to encourage more appropriate use of medical technologies, which may in turn lower medical care costs. The application to a diagnostic technology of techniques for medical technology assessment is discussed, using upper gastrointestinal endoscopy as an example. Several generic problems are often encountered when performing an assessment of a diagnostic technology. These problems include the need to weigh relatively concrete data on clinical and economic costs against less quantifiable data on the value of the information gained from the procedure. In the case of upper gastrointestinal endoscopy, data on morbidity (approximately two cases per 1,000 cases), mortality (approximately one case per 20,000 cases), changes (approximately +290 per procedure), and costs (between +69 and +128 per procedure) are relatively easily determined. Less easily calculated is the marginal diagnostic gain from endoscopies performed for the wide variety of conditions for which an endoscopy may be indicated. It is concluded that, in the case of diagnostic technologies, technology evaluations may be most useful as a heuristic tool. Because of the difficulty in weighing costs and benefits, however, formal evaluations of diagnostic technologies are not likely in the near future to contribute to medical care cost containment.