Clinical evaluation of diagnostic tests, part II: The pitfalls

In a climate of limited health care resources, evaluations of the usefulness of diagnostic tests will flourish. Since the impact of these evaluations will be great, the health care community must ensure that they are performed as carefully as possible. All health care professionals must be able to recognize the errors and limitations of current evaluation techniques. Errors in evaluating diagnostic tests can occur at the time of data collection, the time of data analysis, or when a test is used in a clinical setting. Many errors can be avoided with careful planning. In this article, patient spectrum errors, test result errors, association errors, and test utility errors are discussed.