Before medical tests are introduced into practice, they should be properly evaluated. Randomized trials and other comprehensive evaluations of tests and test strategies can best be designed based on an understanding of how tests can benefit or harm patients. Tests primarily affect patients' health by guiding clinical decision making and downstream management, such as the decision to order more tests or to start, stop, or modify treatment. In this article, the authors demonstrate that tests can have additional effects on patient outcome, which may be cognitive, emotional, social, or behavioral. They present a framework to help researchers and policy makers consider the cognitive, emotional, social, and behavioral effects of testing. These additional effects may be important themselves and may also influence the clinical outcomes of testing through different pathways. The authors provide examples from test evaluations in the literature to illustrate how these additional effects can be important in the evaluation of testing or indeed any health intervention.