Methodological review reveals essential gaps and inconsistencies in clinical claims, effects, and outcomes in HTA reviews of diagnostic tests

Health technology assessments (HTAs) are reports that assess whether medical tests, technologies, or treatments are worth using. HTA reports consider both effectiveness (how well something works) and costs. Tests can affect patients in many ways. It is important to understand the accuracy of a test as well as other impacts it may have on an individual's health and care. An important first step for an HTA of a test is to describe how the new test fits into regular medical care. A second step is to describe how the test could benefit, or harm, patients compared to regular care. HTA authors can then make sure that the result of using the test is measured using the right outcomes. We looked at 50 HTAs of medical tests that were written in English. We found that almost all reviews (98%) explained where and when the test would be used in patient care. About two-thirds of them (62%) included diagrams to show this. Only half clearly stated how the test could benefit, or harm, patients. There was often a disconnection between the expected benefits and harms from use of the test (clinical claim for the test) and the effects from the test that the authors of the review set out to assess. This could lead to the wrong conclusions about how well the test works and whether it is worth the cost. We also described broader effects of tests on health-care systems and society. A more structured approach to help describe how a new test fits into regular medical care and to identify what a test claims to do is needed. This would help to ensure that all important outcomes are measured.