Economic evaluations of diagnostic testing

Healthcare costs worldwide have surged in recent decades. For example, the United States spent 1.55 trillion dollars on healthcare in 2002, or 14.9% of its gross domestic product (see http //www.cms.hhs.gov/statistics/nhe/historical/tl.asp, accessed March 18, 2004). Although the direct laboratory costs are small in comparison, the tests have a profound influence on medical decisions and therefore total costs. 

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Marshall DA, O Brien BJ. Economic evaluation of diagnostic tests. In Price CP and Christenson RH, eds. Evidence-based laboratory medicine from principles to outcomes. Washington DC AACC Press, 2003 159-86. 

Two reviews of economic evaluations of diagnostic tests have shown poor adherence to the criteria outlined above, with only about half of the evaluated papers meeting the criteria. ... 

Severens JL, van der Wilt GJ. Economic evaluation of diagnostic tests. A review of published studies. Int J Technol Assess Health Care. 1999 15 480-96. 

Cost minimization can be considered as the simplest approach and provides the least information it is an evaluation of the costs of alternative approaches that produce the same outcome. In the area of diagnostic testing, it is applicable only to the cost of alternative suppliers of the same test, device, or instrument. It is therefore a technique that is limited to the procurement process where the specifications of the service are already established and the outcomes clearly defined. It might be considered as providing the cost per test, an often quoted parameter that is not, however, a true economic evaluation because it does not identify an outcome except the provision of a test result. 

Besides their utilization in the production of many compounds with therapeutic, diagnostic, and immunizing applications, animal cell cultures have undoubted utility in the performance of in vitro cytotoxicity tests. They can be used for the evaluation of potential anti-neoplastic agents and assessment of the safety of various products, such as pharmaceuticals, cosmetics, alimentary additives, pesticides, and industrial chemical products. Cell culture systems are frequently employed in the cancer chemotherapy field, in which their potential value for viability and cytotoxicity tests is largely accepted. Animal models play an important role in toxicity testing, but the pressure to adopt in vitro tests is growing since they present considerable economical advantages over in vivo tests. The use of animal models is limited to human metabolism studies, and there are... 

In exactly the same way as for studies on diagnostic performance and for outcomes studies, there is a minimal set of criteria for evaluating an economic study of a diagnostic test. A suggested list of criteria includes ... 

The perspective from which an economic evaluation is performed affects the design, conduct, and results of the evaluation. The perspective may, for example, be that of a patient, a payer (government health agency or health insurance company), or society. The perspective may be long term or short term. The perspective is a practical consideration when attempting to assess the benefit of a particular test or device as part of a more complex clinical protocol. Perspective is also important in relation to many of the routine decisions made about a diagnostic test. The questions below illustrate the importance of perspective ... 

Economic Analysis is vital to justify the implementation of new diagnostic tests into resource limited health-care systems. POCTs are often more expensive on a test-by-test basis due to the scaling and portability of devices and not benefiting from the efficiency of large-scale multiplex laboratory testing of multiple samples. However, POCT can have benefits further down the clinical pathway such as those described in Table 2.1. These indirect cost savings can only be established by performing a comparative evaluation of the clinical pathway with and without the test. 

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